Ultimate AMD PC: what to buy and how to build it
20th Dec 2012 | 13:00
Are AMD CPU's really the weak link we've been led to believe?
The time has come to give AMD another chance. Chuck out all your assumptions. Forget everything you've learned or read about its products.
In short, make today ground zero for your relationship with the world's alternative CPU supplier, and the only company that can flog you the complete end-to-end package of CPU, motherboard chipset and performance graphics.
We're not talking about turning AMD into a charity case, and this isn't about making big allowances, though anything that keeps AMD afloat and ensures there's more than one player in the processor market is extremely welcome.
It's about focusing on what really matters when it comes to PC performance and value for money. It's about not being distracted by often arbitrary benchmark results. It's about building a PC based on what it will actually do, not how it compares to something else.
The first assumption we want to challenge is that AMD's processors are the weak link. There's no question that Intel's CPUs are faster, but does that matter? For several years, Intel has been sandbagging its mainstream CPUs, so it clearly thinks there's only so much CPU performance you need.
15 best graphics cards in the world
A big part of this process is to revisit AMD CPUs in the context that matters to us: games. The thing about games is that you need a minimum level of performance, but don't benefit much from large multiples of that. In other words, dropping below a certain frame rate is very bad, but whether you have twice or 10 times that rate is fairly inconsequential. If you've got a bit of a margin, that's fine.
Moreover, as soon as you shift the emphasis to what's good enough rather than what wins in benchmark fisticuffs, you can take a much more balanced view of configuring your system. Suddenly, the merits of going end-to-end with AMD and pairing good-enough CPUs with excellent GPUs might make sense. It's a bold experiment.
Maybe it won't work and AMD's CPUs are the weak link after all. But with Intel locking down features and locking out joy of ownership, it's got to be worth a try.
Since we're asking you to reboot your relationship with AMD, it's only fair if we come clean too. We've probably been too keen to beat the Intel drum when it comes to PC performance. That's not because Intel doesn't make the fastest CPUs. By any sane and objective measurement, Intel's chips are the quickest, and the most powerful you can buy for a PC. We've haven't been wrong about them in that sense.
Put another way, the problem isn't that Intel doesn't make great products. It does, but almost everything about the way it markets and sells the things stinks. What's more, simple and objective measurements of raw CPU performance are only one part of the story here. Intel itself has tacitly conceded that CPU performance has become a non-issue.
That's why its mainstream processor models have topped out at four cores for the last four generations. There's only so much CPU performance most people need, and a modern quad-core chip does the job just fine.
That's why Intel's six-core PC processors are really server chips that in turn require a silly, overly complex server platform. Okay, it's not hard to think of a situation where sheer CPU grunt makes all the difference. If your PC's chief workload is crunching high quality video encodes, you want to throw as much money at the CPU as humanly possible. But be honest - does that really resemble how you usually use it?
Kepler architecture in-depth
A more realistic scenario involves a pretty mixed bag of applications and software, and if you're anything like us, quite a lot of games. Suddenly, the whole question of how you should specify your PC becomes more nuanced. How should you balance CPU and GPU in your overall budget? Are you gaining or losing from an overall platform perspective?
Things get even more complex when you throw Nvidia graphics into the mix. In fact, the latest Kepler generation of Nvidia graphics chips are a great example of how certain assumptions can distort the market.
But we'll come to that in a moment. First, let's revisit the pros and cons of AMD's current CPUs and have a little think about the reasons why they've fallen so far out of favour.
Much of it comes down to expectations that work on many levels. For starters, the computing industry has us trained into a state of perfect - you could say Pavlovian - expectation. Either Intel or AMD rings the bell of a new generation of chips, and we all drool in anticipation of mighty performance gains. Anything else is seen as a rank failure.
We don't just want a new chip to be better overall - we're offended if it seems to fall short in any area, and we're offended if it's not the fastest thing out there. Therefore, AMD's FX processors based on the Bulldozer architecture received a frosty reception at launch. Overall it's a step forward over AMD's Phenom II CPUs, but it's still a long way off Intel's finest.
Its greatest sin was to be slower in some areas - most notably single thread performance - than its Phenom II progenitor. In the context of PC technology any sort of step backward is awfully hard to stomach, but a new processor that was slower at crunching a single thread of code? Unforgivable.
This month, we want to comprehensively reassess that assumption and reboot the thinking process, because what matters isn't performance relative to Intel. What actually matters is whether AMD's chips are good enough. If they are good enough, we can then begin to look at all the other factors, like pricing and platform comparisons.
Without doubt, there are plenty of reasons to like AMD chips. Reasons like AMD's support for existing customers by maintaining socket compatibility for as long as humanly possible. It just gives you more options when it comes to upgrading either your CPU or motherboard.
The way Intel does things - particularly with the transition from LGA1156 to LGA1155 - sometimes seems like change for change's sake; a cynical ruse to force you to buy a new motherboard and CPU together.
Don't forget, third-party chipsets no longer exist, so any Intel motherboard you buy means money trickling into Intel's coffers. Likewise, it's nice to have full ownership and control of the product you just paid handsomely for.
Increasingly, Intel is locking out access to features and functionality depending on price. Thus, some dual and quad-core processors have HyperThreading switched off, despite it being there in the hardware, and all but Intel's K Series and Extreme Edition chips have mostly locked or entirely locked CPU multipliers, putting the kybosh on overclocking. Meanwhile, all AMD FX processors are fully unlocked, and there aren't any features hidden away out for marketing reasons.
On the graphics side, of course, it's Nvidia that's providing the uncomfortable comparisons. AMD has generally been a lot more competitive when it comes to pumping pixels than it has crunching raw code, but there's still been the odd dropped ball, such as the Radeon HD 2000 and, to a lesser extent, 3000 series.
The association with AMD's ailing CPUs hasn't helped the branding effort either. That only looks worse when the competition seems to have the edge. When Nvidia's GeForce GTX 680 (the first card from the new Kepler generation) appeared, it seemed like there was something unnatural going on. Here was a relatively compact graphics chip with a transistor count much lower than we were expecting from a new flagship GPU at the time, and yet it had the measure of AMD's larger, much more complex Radeon HD 7970 in the benchmarks.
As it happens, the situation mirrored the comparison between AMD's Bulldozer chips and the Intel Core family of processors. In both cases, AMD's technology looked bloated and inefficient next to the competition. Perhaps that's why Nvidia's explanation for the performance of Kepler cards seemed so plausible.
In any case, it combined with that well-established shortfall on the CPU side to give the impression of AMD as an also-ran. Given the choice, you'd pick Nvidia.
The explanation for the efficiency of the Kepler generation seems plausible enough, too. This time around, Nvidia has focused on maximising graphics performance to the detriment of general purpose workloads running on its GPUs, otherwise known as GPGPU, so a whole hunk of transistors can be chucked out without hurting games performance. That's the theory.
The problem is, graphics performance is an awful lot more nuanced than CPU grunt. Broadly speaking, you can get a good idea of CPU performance with just a few tests, and it's unlikely you'll uncover anything nasty and surprising down the road.
For the most part, that's because CPUs are general purpose items. Yes, there is some separation of work loads when it comes to integer versus floating point performance, and some architectures can get caught out by things like cache performance and memory bandwidth, which will only show up in certain applications. But on the whole CPUs are as CPUs do.
Not so for graphics. The key difference is that GPUs are still effectively fixed function processors. Programmability has increased enormously compared to chips of a decade ago. But you'll still find things like texture units, rasterisers and render output units in modern GPUs.
What's more, even the most highly programmable units - the stream processors - aren't general purpose to anything like the same extent as a CPU core. The upshot of all this is massively more scope for inconsistent performance, at least in comparative terms.
So one GPU might be a monster at calculating pixel shaders at a certain precision level, but be really pants when it comes to tessellation. We don't want to give away too much at this stage. But let's just say that there are areas where Nvidia's decision to hack out a lot of hardware from the Kepler generation suddenly makes itself apparent where it matters: in games.
The final major piece of the puzzle is the underlying platform - the motherboard and its chipset, in other words. It's both good and bad news that third party chipsets essentially no longer exist.
You'll need an AMD chipset to go with your AMD CPU, and the same applies to Intel hardware. Less choice is less confusing, but on the Intel side of the equation it adds to the sense of a lack of competition.
Here again, Intel's awful marketing rears its hideous head. The result is chipsets with features arbitrarily locked out. For instance, Intel only allows overclocking with certain chipsets. Combine that with the limited number of overclockable CPU models and you find yourself completely backed into a corner when it comes to building an Intel rig, with very little choice over models and prices.
Intel's track record for supporting existing customers is awful, too. It recently announced that it had finally cracked the problem of support for the all-important TRIM command for SSDs used in RAID arrays, and there was much rejoicing. Then we learned the software update would only be made available for the latest 7 Series chipsets. We're pretty sure that there's nothing in the hardware to prevent the update being made available for, say, 6 Series chipsets. It's just Intel's way.
We're not convinced Intel is really pushing the envelope when it comes to chipset features, either. Okay, Intel deserves credit for pushing through PCI Express 3.0 on the 7 Series chipsets, but why did it take so long to include USB 3.0 natively?
And what the rubbery duck is going on with Intel's SATA 6Gbps support? Here in the cold, harsh light of 2012, you still only get two out of six SATA ports with 6Gbps support with most 7 Series chipsets (with the exceptions you only get one). And this in an environment in which SATA 6Gbps, much less the slower 3Gbps standard, is already holding back performance with the fastest current SSDs.
Meanwhile, AMD has been supporting 6Gbps SATA across the board with many chipsets for the past two generations. Admittedly, AMD has yet to include USB 3.0 on its mainstream desktop PC chipsets. For now, only its chipsets for the A Series Fusion processors get native USB 3.0 treatment.
Then there's the end-to-end argument. Much to Intel's chagrin, only AMD can offer a full solution for your PC: a decent CPU, a decent motherboard chipset and decent graphics. Intel still can't do the graphics. That's why AMD has been bigging up the overall platform proposition of late, claiming there's a tangible benefit to running AMD CPUs and GPUs together.
Much of the reason for that strategy is the simple fact of the relatively weak links that are its CPUs, but it doesn't mean there's no truth to it.
Ultimately, all of this adds up and all of it matters. If, for instance, Intel didn't lock down overclocking to a small handful of PC processors. If it didn't lock down overclocking to certain chipsets. If it supported its existing customers more fully. If it was pushing the envelope of mainstream PC performance and features instead of sandbagging. If it sold its wares based on merit rather than marketing nonsense. If all of that was true, we wouldn't be here, begging you to reconsider AMD.
As we've said before, Intel has great products. But Intel does lock down its products, sneer at existing customers and sandbag on an increasingly epic scale. Just as important is the question of whether AMD's CPUs are good enough rather than how they compare to Intel products. If they are, suddenly there's a very strong case for choosing them.
Admittedly, we're not dealing with any new products here. We've taken four-core, six-core and eight-core versions of AMD's FX chip, and matched them with AMD motherboards and graphics. All are well known quantities, but that's the point - maybe it's our attitudes and not AMD's products that are really in need of a refresh. Let's find out.
Reaching ground zero for the AMD argument
Let's start at the beginning with the lowest of the low. If we can make an argument for building a rig based on the supposedly feeble four-core version of AMD's oft maligned FX processor, surely the job's a good 'un when we finally arrive at the four six- and eight-core processors?
Lest you have forgotten, four-core AMD FX processors are barely even that. The radical Bulldozer architecture sees a single processor module sharing several computing resources, including fetch and decode engines and the floating point execution unit. Okay, the integer units are doubled up. But four AMD FX cores aren't the same as four Intel cores. Or four of AMD's old Phenom II cores, for that matter.
If you were being really harsh, you could call an AMD module a glorified core with dual-thread capability and thus any AMD FX 4000 series chip is merely dual-core. Crikey.
What's more, the days of buying AMD processors and unlocking hidden cores in the motherboard BIOS are dead. It's not possible with FX chips. Then again, the FX 4170 model tested here is the quickest of the 4000 series and clocks in well above 4GHz.
As we know, not many games scale well beyond four threads, so maybe fewer cores but higher clocks makes sense. But what to pair it with?
This is our entry-level platform, which makes our chipset choice straightforward. AMD's basic 9 series effort, the 970, makes a lot of sense. It makes for an affordable motherboard but gives you the best chance of long-term compatibility and upgrades.
Since it's the latest generation chipset, critically it doesn't skimp on bandwidth. You get the latest 3.0 version of HyperTransport and SATA 6Gbps across the board. Yes, you'll miss out on a few frills, such as support for umpteen graphics cards in CrossFire multi-rendering mode. But where it matters, the 970 is more than adequate.
Next up is graphics. At this end of the market, the best bang for buck often comes from recently replaced cards from the previous generation. Similarly, the second-tier chip in any graphics family tends to be the most cost effective and, in turn, the second rung SKU of said GPU usually pumps the most pixels for the fewest pennies. Follow that philosophy to its logical conclusion and you end up with an AMD Radeon HD 6850.
And the net cost of all three of these core components? The FX 4170 is yours for just £93, 6850s can be had for about £85 and 970 boards start as £50. That's well under £250 for the complete package. Add memory, a PSU and maybe a 120-odd GB SSD (we'll assume you've some kind of Windows OS licence) and you can assemble the whole shebang for under £400. Pretty bloody compelling, eh?
But what about the reality? As we've already explained, the question here isn't whether you can pay more and get something faster. It's whether this platform is fast enough in isolation. And the simple answer is that most of the time in most games, this is a remarkably playable set up.
Of course, you can get just about any fairly recent PC running a game if you switch off enough of the eye candy. So our worry with this entry level rig was that we'd have to crush the details down horribly to achieve vaguely playable frame rates.
For the most part, that's simply not the case. Take Max Payne 3. With most of the details maxed out and both anti-aliasing and tessellation enabled at 1,920 x 1,080, the bargain basement solution pulls an average of 29 frames per second. Marginal? Yes. Playable? Just about.
Switch off anti-aliasing and you're looking at frames in the high 30s. Knock tessellation on the head (which frankly isn't all that dramatically implemented in Max Payne 3 much of the time) and you'll approach an average of 50 frames per second. That's nice, smooth gaming by any metric.
The choice is a little more stark with games like DiRT Showdown. Hit the Ultra switch and the combination of global illumination and busting out of the test card's 1GB frame buffer dragged the average frame rate at 1,920 x 1,080 down to just 16 frames per second. However, with the global details set to high and with anti-aliasing enabled, the result is a remarkable average of 56 frames per second.
And let's be honest. You'd struggle to pick the High setting from the Ultra setting in a blind test. They both look great.
The results in Just Cause 2 are even better. Crank pretty much everything to maximum and wind up the anti-aliasing to 4x and you'll still get 44 frames per second average. Nice.
If there's one game in our suite that gives us cause for a pause, it's Metro 2033. In many ways, it's the best-looking game in our test suite and it's certainly the most demanding. Choose the Very High global detail setting, enable 4x anti-aliasing and pump 1,920 x 1,080 pixels and the result is 17 frames per second. Yuck. Turning off the anti-aliasing doesn't help significantly, but step back from Very High to High and you will get an average of just under 30 frames per second and a gaming experience that's just about playable.
As for pure CPU performance, well, you're looking at getting roughly half the speed of a good Intel quad-core processor. The same goes, unsurprisingly, for an AMD FX processor in eight-core and four-module trim. But then it's always been clear that CPU performance is critical for things like video encoding.
The interesting question here, of course, is whether it's the graphics, the CPU or a bit of both holding back the performance when the gaming frame rates do drop a little.
Chipset: AMD 970 with SB950
Storage: 6x SATA 6Gbps USB 8x USB 2.0, 2x USB 3.0
Memory: DDR3 up to 1,866MHz
Graphics: 1x PCIe 2.0 x16
If it's the ultimate in bang for buck you seek, you'll struggle to beat a budget motherboard as you just get so much hardware for your money. Okay, there are cheaper boards based on the AMD 970 chipset, which is the entry level 9 Series effort.
Gigabyte's own 970A-DS3 can be had for a mere £70 or so. But we reckon the UD3 motherboard makes for a slightly better long-term proposition. For starters, you get better cooling for the chipset, the MOSFETs and all that.
Then there's better audio with 5.1 surround and optical-out. Moreover, it's not missing out on anything when it comes to the most important kit which determines raw bandwidth. That means six SATA 6Gbps ports and a pair of Etron USB 3.0 chips for a total of four USB 3.0 channels, double the number provided by the 970A-DS3.
XFX Radeon HD 6850
Chipset: AMD Radeon HD 6850
Memory: 1GB GDDR
Memory: bus 256-bit
Core clock: 775MHz
Stream shaders: 960
Process technology: 40nm
At this end of the market, something's got to give. You can't have the very latest technology from the very biggest GPU combined with a ton of graphics memory. However, if you wind back the clock a little and go with something from the previous generation and the second tier of the product range, you still get an awful lot of graphics processor for under £100.
Take, for instance, the 960 DX11-capable stream shaders for starters. However, if there's any single statistic that confirms the HD 6850's status as a pukka pixel pumper, it's the meaty 256-bit memory bus. At high detail and resolutions, bandwidth is king.
It's a little ironic, therefore, that this board's greatest weakness is also memory related. At 1GB, it simply doesn't have enough of it.
AMD FX 4170
Clockspeed: 4.2GHz, 4.3GHz
Turbo Cache: 4MB L2, 8MB L3 Socket AM3+
Process technology: 32nm
Memory: DDR3 up to 1,866MHz
If any CPU is going to make or break the theory that AMD's chips might be good enough after all, it's the FX 4170. With just two modules and four AMD-style CPU cores, it seems to be the worst of both worlds. By that we mean you suffer the poor per-thread throughput of the Bulldozer architecture and only have a couple of modules and a quartet of threads to make up for it. Run. Run for the hills!
Indeed, in traditional CPU tests like professional rendering or video encoding, the results are pretty predictable. The FX 4170 is slow. But what about games?
In most of our game tests pairing the 4170 with a Radeon HD 6850, performance is surprisingly good. What's more, where it does drop off, there's ample evidence that it's the 6850, not the FX 4170, holding things back.
Budget motherboards offer so much for your money and the Gigabyte GA-970A-UD3 is no exception and AMD's FX 4170 certainly isn't the weak link that you might expect. Instead, it's the Radeon HD 6850's measly 1GB of memory that's the problem.
Final verdict: 3/5
Upping the ante to six cores and Radeon HD 7 Series graphics
Enough is enough. That's the philosophy underpinning this entire AMD escapade. Forget about performance for performance's sake. Don't go chasing 150 frames per second when 50 feels fine.
Of course, you can overdo the penny pinching too. In that context, it's this mid-range solution that really nails it on paper. For starters, we've added an extra Bulldozer CPU module courtesy of a six-core FX 6000 series CPU. Given that the Bulldozer design is all about efficient performance scaling with multiple threads, it makes sense to up the core count a bit.
In the process we've lost a little in the sheer frequency stakes compared with the dual-module, four-core FX 4170 from the budget rig. But we're still talking more than 4GHz in Turbo mode. The FX 6200 is no slouch.
If our argument makes any sense, however, even more significant is the upgrade from last-generation AMD Radeon HD 6850 graphics to a board sporting a spangly new Radeon HD 7000 series GPU. As this is a mid-range setup, maximum bang for buck is what it's all about, and the second-tier GPU in second string trim is where it's almost always at. Enter a Radeon HD 7850, right?
Actually, no. A brief perusal of prevailing pricing revealed that the gap twixt the HD 7850 and the slightly superior 7870 was only slim. Critically, we're talking about the comparison between boards with 2GB of memory. There are some super-cheap 1GB 7850s out there, but in our view, they're very much a false economy. A mere 1GB of memory isn't enough to run the latest games at high detail settings and full HD 1080p. You run out of memory and end up swapping graphics data over the PCI Express. And that absolutely hammers your frame rates, and in turn blows this whole AMD argument apart.
A Radeon HD 7870 with 2GB of memory it is, then. Again, we're mostly interested with performance in isolation. But in comparison terms, the yardsticks are the entry level AMD rig overleaf and an Intel platform powered by the more expensive combo of an Intel Core i5-3570K CPU and a Z77 chipset.
Straight out of the blocks, it's apparent that the FX 6200 chip and 7870 graphics are operating on a higher level than the cheaper AMD platform. With one exception, the games in our test suite are slick, smooth and playable at 1080p with the eye candy maxed out and 4x anti-aliasing.
Take Max Payne 3. It steps up from 29 frames per second with the FX 4170 and Radeon HD 6850 to 42 frames per second. Even more impressive, DiRT: Showdown ticks along at fully 38 frames per second, even with global illumination enabled.
As for Just Cause, this mid-range machine gives it a solid 74fps spanking. The only snag is the beautiful but demanding Metro 2033. An average of 25 frames per second isn't good enough. Step down from very high detail to high detail, turn off anti-aliasing and the result is a much more palatable 37 frames per second and genuine playability, though you can still expect the odd stutter and stall when things get really messy on screen.
In isolation then, this setup doesn't quite achieve the Holy Grail of no-worries gaming. Put another way, you can't fire up any game, set everything to maximum and know you're going to get playable frame rates. That will work most of the time, but just occasionally, you'll be disappointed.
But what if the same is true of the Intel platform? Well, guess, what? It actually is. We ran that Core i5-3570K and Z77 chipset with precisely the same Radeon HD 7870 board. And get this. It was only one frame per second faster at maximum. One pathetic frame. It's not a lot considering the Intel combo will cost you well in excess of an extra £100.
Admittedly, the gap in Max Payne 3 was bigger. Intel's 52 frames per second plays AMD's 42fps, but as we keep saying, it's not the digits that matter, it's the experience. And in all likelihood you'd no more notice 52 versus 42 than 26 versus 25. In both cases, Intel's victory is purely academic and doesn't justify the price differential.
That's an absolutely fascinating result when you bear in mind that the Core i5-3570K annihilates the FX 6200 in traditional CPU tests. Cinebench 11 is a nice example. Intel scores just over six points. AMD can only manage 3.76.
It's a similar (if slightly less extreme) story with x264 HD video encoding, with Intel cranking out 34 frames per second to AMD's 27. Unless you have a habit of sitting there and watching rendering or encode jobs do their thing, however, how much does that matter?
Whatever, the comparison between the Core i5 and AMD FX here proves that your money is better spent on graphics than CPU power. There's a £60 price gap between those two chips and given a limited budget, we're completely convinced you'll get more gaming mileage piling that money into the best graphics card you can manage.
At this stage we probably need to emphasise once again that we're not saying there's no difference between the AMD and Intel CPUs here. Our benchmarks of recent years have not been wrong. We've not uncovered a hideous flaw in Intel's CPU architecture. All we've shown is that the difference is mostly, if not entirely, inconsequential when it comes to the experience.
It's thoroughly liberating to be able to say that. Trust us, year after year of predictable CPU reviews with the same company winning over and over is no fun. If you've got the money, Intel is a great choice, but it's not the only choice. And that's probably something we haven't emphasised enough.
Chipset: AMD 990X with SB950
Storage: 6x SATA 6Gbps USB 8x USB 2.0, 2x USB 3.0
Memory: DDR3 up to 1,866MHz
Graphics: 1x PCIe 2.0 x16, 1x PCIe 2.0 x8
Make no mistake. In pure performance terms, you'll get away with a cheaper motherboard based on the 970 chipset, like Gigabyte's GA-970A-UD3. In fact, you'd be just fine with an even cheaper 970 for around £65. But for less than £20 extra, this 990X is certainly worth a look.
The extra cash buys you MSI's Military Class components throughout, including solid capacitors and super ferrite chokes. If that means nothing to you, the bottom line is improved stability and reliability. What's more, you also get MSI OC Genie auto-overclocking utility, albeit without an easy-access button.
Oh, and there's support for both CrossFire and SLI in dual-card mode courtesy of the x16 and x8 PCI Express 2.0 ports. The latter means you've got all the major bases covered in terms of features and technology. That's got to be worth a few extra quid.
AMD RADEON HD 7870 GE
Chipset: AMD Radeon HD 7870 GHz Edition
Memory: 2GB GDDR
Memory bus: 256-bit
Core clock: 1,000MHz
Stream shaders: 1,280
Process technology: 28nm
We're in reference card territory here in terms of our test board. But for the record, you can snag a 2GB Radeon HD 7870 board with a core clock in excess of 1GHz for just under £180.
For that you get a 256-bit beast that can very nearly handle anything you bung at it. Hang it all out at 1080p and this card just delivers. With one exception: it couldn't quite stomach our challenging Metro 2033 benchmark. Not at full detail with anti-aliasing enabled.
That said, the 7870's most impressive showing is in DiRT Showdown with global illumination enabled. The supposedly mighty combo of Intel Core i5-3570K and NVIDIA GeForce GTX 670 crumbled in the face of that test. But the little old 7870? Paired up with an AMD FX 6200 six-core CPU, it absolutely flies.
AMD FX 6200
Clockspeed: 3.8GHz, 4.1GHz
Turbo Cache: 4MB L2, 8MB L3
Process technology: 32nm
Memory: DDR3 up to 1,866MHz
Most games don't scale well when you add CPU cores. We didn't think we'd be saying that in late 2012, and yet the brave new world of massively multi-core computing we were promised by Intel and others as long as five years ago still hasn't turned up.
In that context, you might not fancy this six-core AMD FX's chances. But here's the thing. Some games do scale beyond four threads. Then factor in a mere £20 price gap between this chip and the four-core FX 4170 and there's really no decision to be made. You want the 6200.
Arguably even more surprising is that on the evidence of this test, you won't get a tangible benefit from an upgrade to something much more expensive from Intel. Yup, the benchmark numbers will be better. But that's about it.
The AMD mid-range option comes awfully close to delivering flawless gaming performance, and excellent all-round value. This setup balances price and performance without sacrificing either.
Final verdict: 4.5/5
The ultimate in AMD
Does pure AMD make sense at the high end?
The core of the argument for AMD boils down to two notions. Firstly, there's the real-world experience - our 'good enough' concept of gaming performance. Then there's value for money. With that in mind, the notion of flinging significant quantities of folding cash at an AMD-only gaming rig doesn't seem like an immediate goer.
But everything's relative. An eight-core FX chip at around £120 is hardly breaking the bank. In fact, that won't buy you a quad-core Intel processor of any kind, much less an unlocked model or a Core i7 example with HyperThreading enabled. That's how yawning the price chasm between AMD and Intel has grown, and it plays directly to AMD's strengths.
Slightly more marginal is our AMD 990FX-based motherboard. It's Asus' Crosshair V Formula-Z specimen, and it retails in the region of £180. It's not the most expensive AMD motherboard in town. The Thunderbolt-enabled version of the same board, for instance, weighs in at a wallet-wilting £270.
But in the context of modern PCs, where so much of the performance-critical componentry resides inside the CPU package, including the northbridge and memory controller, you've got to be realistic about the implications of an expensive motherboard. It's not going to have a tangible impact on performance at stock clocks, even if you might get a little extra overclocking headroom.
More to the point, any money you spend on the motherboard isn't going into graphics, which is the most performance critical part of the gaming package. You could argue that's particularly critical at the high end, where the incremental price gaps between graphics chipsets open into spectacular canyons. Thus, examples of AMD's Radeon HD 7970 kick off at around £300, while you can snag an HD 7950 for just £220.
In pure hardware terms, there really isn't a lot to justify that. The stream shader count drops from 2,048 to 1,792 and the texture units shrink from 128 to 112, but that's it. You get all 32 ROPs, a 384-bit memory bus and 3GB of speedy GDDR5 graphics memory.
Things get a little more complicated when it comes to clockspeeds, especially since AMD rolled out not only 7950s and 7970s with higher frequencies, but also 'boost clock' automatic overclocking feature. It's not always obvious what you're getting, so inspect the specs with care. That said, the real-world difference isn't very dramatic whichever version you go for, making the 7950 the obvious choice, boosted or otherwise.
Anyway, the overall impact of hooking up the FX 8120 CPU, Asus 990FX board and 7950 graphics is pretty impressive. Finally, we've achieved an it-just-works solution courtesy of all-AMD components.
In our benchmarks, the results were the same whatever the game, whatever the setting: smooth, slick and enjoyable gaming. Now, you might view that as a given with this class of components. After all, we're talking about a combined price of over £500 for CPU, motherboard and graphics. That's before you add other essentials like memory, storage, a power supply, a case and a Windows license.
But try this for size. You can't say the same of Intel's Core i5-3570K teamed with a Z77 motherboard and Nvidia's GeForce GTX 670. In some of our benchmarks, there's little to nothing in it.
Max Payne 3 at 1,920 x 1,080 at maximum detail with both tessellation and anti-aliasing enabled? It's 45 frames per second for end-to-end AMD, and 44 for Intel and Nvidia. It's the same spiel for Metro 2033, with AMD pipping the evil Intel-Nvidia alliance 33 to 31 at maximum detail.
Okay, the opposition scores a clear win in Just Cause 2, racking up a mighty 103 frames per second to AMD's mere 89. But again, it's an academic victory; 89 frames per second is plenty quick enough.
However, there is one game where a tangible gap appears - a frame rate differential you can actually feel. And guess what? It falls in AMD's favour. We speak, of course, of DiRT Showdown with that pesky global illumination option enabled. It's a killer for the Intel-Nvidia combo, dragging average frame rates down to 18. Knock the settings back from Ultra to High, disabling global illumination in the process, and performance leaps to 94 frames per second. And the AMD platform? You get a healthy 43 frames per second in Ultra mode with global illumination on, and a modest jump to 63 if you scale back to High and knock global illumination on the head.
To be clear, this isn't Intel's fault. You could pair the Core i5-3570K with an AMD graphics chip and sidestep the issue. In fact, you'll get better results with the Core i5 and a Radeon HD 7870, much less stretching all the way to a 7950. But the overall result doesn't square with the received wisdom. You'd expect the AMD rig to be the one that drops the ball.
As for more general system performance, the extra threadability of the eight-core FX processor in this top-end AMD solution closes much of the gap to that pricey Intel chip. A score of 4.98 points plays 6.01 in Cinebench, and it's 31 frames per second to 34 in x264 HD video encoding. Intel remains clearly quicker, but at a price.
So, there you have it. Even when scaling up the price lists, you can still make an argument for AMD. Don't get us wrong. We're not suddenly suggesting you fling that Intel CPU or Nvidia graphics card out the window. Intel CPUs remain the quickest, and Nvidia's GPUs are far from fatally flawed.
But the AMD alternative is remarkably realistic. Actually, it's more than just realistic. It's competitive at worst and superior at best, and offers more consistent worst-case scenario performance. Remarkable.
Asus Crosshair-V Formula-Z
Chipset: AMD 990FX with SB950
Storage: 7x SATA 6Gbps USB 8x USB 2.0, 4x USB 3.0
Memory: DDR3 up to 1,866MHz
Graphics: 2x PCIE 2.0 x16, 1x PCIE 2.0 8x
If there was a single component we were most dubious about coming into this AMD-gasm, it involved the notion of a high-end motherboard for AMD processors. Surely the extra money is better spent on the CPU and graphics?
The simple answer is yes. The more nuanced response goes something like this: many of the extra features involve functionality few of use are likely to use, like support for triple-card graphics action. We're not huge fans of multi-GPU at the best of times, but support for two cards, as per MSI's 990X board, is certainly sufficient.
On the other hand you get a very nice physical object that will extract the maximum in terms of overclocking, and also offers maximum bandwidth with seven SATA 6Gbps ports and four USB 3.0 sockets. That's nice, but it's not £100 nice.
AMD Radeon HD 7950
Chipset: AMD Radeon HD 7950
Memory: 3GB GDDR
Memory bus: 384-bit
Core clock: 850MHz (925MHz Boost)
Stream shaders: 1,792
Process technology: 28nm
The cut-down version of the incumbent title-holder of world's most powerful graphics chip. That's often the sweet spot when it comes to balancing price, performance, and that most elusive of technological virtues, longevity.
But with value so central to the AMD, is a Radeon HD 7950 a bit of an over-reach? More to the point, can AMD's CPUs keep up?
Funnily enough, yes. AMD FX 8120 plus Radeon HD 7950 makes for a surprisingly effective and consistent package. Certainly it helps that the Radeon HD 7950 has plummeted in price since launch late last year. At over £300, it wasn't very attractive, but at nearer £200 and with some recent fettling in terms of frequencies, it's suddenly quite compelling. This all-AMD idea really is working out rather well.
AMD FX 8120
Clockspeed: 3.1GHz, 4.0GHz
Turbo Cache: 8MB L2, 8MB L3
Process technology: 32nm
Memory: DDR3 up to 1,866MHz
Save for the slightly quicker-clocked 8150 chip, this is as good as it currently gets with AMD processors - and it's yours for just £120. That can't be a good thing for AMD's margins and profitability, but that's not your problem.
Instead, you want to know whether there's any benefi t to having the full four Bulldozer modules and eight AMD-style cores. On balance, we'd say yes. There's only £28 between the 8120 and the two-module, four-core 4170, so you're getting twice the hardware for a lot less than twice the price.
Okay, 8120 clocks are significantly slower, especially when running multi-threaded code. But as an overall compromise taking into account non-gaming performance too, it's the chip we'd choose. And that really isn't what we expected before we dived into this AMD-reassessment endeavour.
Proof positive that an all-AMD solution can cut it with modern games. Sometimes it even out-performs the competition. A properly slick gaming platform, but the motherboard is too pricey.
AMD mix 'n match
Building a more balanced rig
As soon as you set out on this sort of endeavour, you know there will be compromises. For instance, slipping AMD's kit into three neat little categories - bargain basement, mid-range and high-end - helps to quantify the argument. But it's also very restrictive.
That's especially true when it comes to maximising your budget for gaming performance. The total price gap between our bargain basement solution and the mid-range option, for example, is around £120. That's spread across CPU, GPU and motherboard.
But what if you stayed the course with the AMD FX 4170 processor and Gigabyte 970 mobo and dropped in a Radeon HD 7950? Could AMD's entry-level FX chip cope? Would it be graphics overkill?
The same applies for the step from mid-range to high-end. The delta's even bigger there, clocking up to £160 for graphics, processor and motherboard. It's certainly tempting to slap that all into graphics. But again, is the lower specified processor and motherboard up to the task? Let's find out.
In the interests of maintaining a little suspense, let's kick off with the midrange option. To recap, the default setup here is: AMD FX 6200, a six-core effort with 3.8GHz/4.1GHz Turbo clocks, and MSI's 990XA-GD55 motherboard. The natural partner in terms of graphics feels like a Radeon HD 7800 board of some flavour and it was the 7870 GHz Edition we went for.
But what happens when you sling in some 7900 Series silicon in the shape of a Radeon HD 7950? The answer is that it depends on the game in question. But get this: the worst-case scenario is that you get games performance at least as good as the full-on high-end platform complete with 990FX motherboard and eight-core FX 8120 processor.
In Metro 2033, the most demanding of our gaming quartet and, therefore, the title that provides the most critical baseline, the mid-range mashup delivers identical results across the board to the pure high-end solution. There's not a lot in it in Max Payne 3, either.
Most likely, that's because these are games predominantly limited by GPU performance. Elsewhere, the CPU comes into the equation and that's when the combo of mid-range CPU and high-end graphics is actually more effective. DiRT Showdown with anti-aliasing and global illumination disabled is probably the best example here. The full high-end rig scores 61 frames per second versus 67 for our mid-range mashup.
Counter intuitive? It would be if games were like video encoding and scaled neatly across as many cores as you throw at 'em. But they're not, so the explanation very likely centres on the 6200's significantly higher clocks. It's true that they're very close in terms of maximum Turbo speed. But that only happens with a single core under load. While most games won't generate infinite CPU-intensive threads, most are capable of at least a few.
That's the worst possible scenario for the eight-core FX 8120 - enough threads to prevent full-speed turbo but not enough to capitalise fully on its extra cores.
With that in mind, the prospect of a low-end CPU and high-end graphics doesn't seem so crazy after all. Remember, the FX 4170 has the quickest clocks here, buzzing along at 4.2GHz even with all four cores loaded. Could the cheapest CPU actually be the best?
In a word, no. When it's the graphics card throttling performance, for instance Metro 2033, the 4170 does just fine. But in less demanding games, a gap does emerge. It's not necessarily a crippling, deal-breaking delta in performance. But if our benchmarks are anything to go by, you'll be limited to around 45 frames per second in most games. That's tolerable today, but you've absolutely no margin left for the ever more CPU-intensive titles that will inevitably appear in future.
But the killer blow for the 4170 involves pricing. It's simply not available at a big enough discount. You'd be insane not to go for the six-core 6200 for the extra tenner. The choice between the 6200 and the full-on eight-core 8120 is more nuanced.
Again, the price gap is modest, with £20 between them. We'd be tempted to go with the 8120 and crank up the clocks a little. But the argument is finely balanced.
At this stage, we're getting awfully close to an overall conclusion. But there's still one question we haven't directly addressed. Is there anything to AMD's claim that there's a direct, tangible benefit to a pure, end-to-end AMD setup?
It's difficult to get a completely definitive answer here. But we've mixed and mashed with a view to flushing out as many facts as possible. Along with the three AMD platforms, the two mashups we've already discussed above and the reference Intel-plus-Nvidia shebang, we added a few more combos to the mix.
We've got the Intel Core i5-3570K running with an HD 7870, the AMD FX 6200 with AMD GeForce GTX 660 Ti and the FX 4170 with a GTX 460. And the results? In truth, they're inconclusive.
The most direct comparison is the Core i5 and the FX 6200, both running Radeon HD 7870 graphics. For the most part, the Intel-plus-AMD gives better results. The one exception is DiRT Showdown at full detail with that GPU-bashing global illumination option enabled. Here, AMD-plus-AMD is up to 30 per cent faster. It's probably the difference between playable and not playable.
Like we said, it's difficult to be certain about what exactly is going on here. However, it does hint that there may be some truth in AMD's end-toend claims. Not the clinching argument then? Nope. But it does feed into a broader picture that looks far more positive for AMD than we were expecting.
How we tested
No-compromise gaming is what we're interested in here. Proper, modern games at really high settings. We want to know if full AMD platforms can cut it.
Don't worry, therefore, about frame rate comparisons. Focus on the bottom line. Does a given platform deliver playable frame rates? Along with the three core AMD platforms and the reference rig built from Intel and Nvidia kit, we've thrown in some mashups.
First, we dropped the Radeon HD 7970 into the low-end and mid-range AMD platforms. We also tried Nvidia graphics with AMD and, in turn, AMD graphics with an Intel CPU.
And the winner is… AMD (and your wallet)
We've run a few features of late aimed at exploding conventional wisdom. One of the best involved a contest between a £300 and £3,000 system to see if paying more made a tangible difference. Sure enough, our expert game testers couldn't tell the difference in blind tests. So much for cutting-edge kit.
But the results of this all-AMD escapade are easily the most dramatic of the lot. The context coming in was two-fold. On the one hand, there's Intel's absolute domination in terms of outright CPU performance. It's been going on for years. On the other is Nvidia's Kepler generation of graphics cards, which seemed to have the edge over AMD's Southern Islands crew.
For the CPU half of the equation, you could argue that we've learned nothing new. Even Intel's mid-range Core i5-3570K has a clear performance advantage over anything AMD can offer. But the emphasis here is that outright, objective measures of performance are irrelevant. What matters is the subjective computing and gaming experience.
Then factor in how much you're paying for it and you're in a much better position to pick a PC processor. In truth, we weren't entirely confident that AMD's kit could really hack this sort of scrutiny, but the oft-maligned FX processor performed far beyond our expectations.
Critically, it delivers good enough performance when and where it really matters. Yes, Intel's Core chips are nearly always faster, but nearly always in a manner you're not going to notice if we're talking games. If you've got 60 frames per second, there's slim to no benefit in adding another 20.
Once you've realised that, all sorts of options open out, especially when it comes to maximising graphics spend, bringing us neatly to the AMD versus Nvidia contest.
This was much closer to begin with, and close it remains, but the evidence that Nvidia's Kepler GPUs might habour a few flaws is beginning to build. There also seems to be at least some truth in AMD's claims that its GPUs work best with its own CPUs.
As to PC Format's overall recommendation, the CPU choice comes down to the six- and eight-core FX options. The quad-core 4000 Series fails on both value and performance grounds, but mainly it's just not cheap enough.
At stock clocks, it's actually the six-core FX 6200 that delivers the best performance thanks to its higher clocks, but an overclocked FX 8120 for just £20 more is awfully tempting.
On the graphics side, we'd beg you to steer clear of anything with less than 2GB of memory. Data swapping over the PCI Express bus must be avoided at all costs. Generally we're going to assume that going with an AMD processor and motherboard has freed up a little cash for you. With Radeon HD 7950s now available for just over £200, you can put together a fantastic all-AMD core component combination for well under £400. Fantastic.
Let's be clear. We're not suddenly reversing our recommendations of recent years, though we have to admit the results come precariously close to justifying that sort of stance. Intel and Nvidia still make excellent kit.
No, what we've really done is show that AMD still has plenty to offer. Much more than we'd given it credit for of late. So, if you're building a new PC, and especially if gaming is your number one priority, all of AMD's product lines - CPU, GPU and motherboard chipset - should be on your list.
Depending on your budget - and we're not merely talking about poverty-spec PCs, there's a real chance all-AMD is the way to go. At the very least, a few more options just opened out. Hallelujah.