AMD Phenom II X6 1090T £200

6th May 2010 | 15:45

AMD Phenom II X6 1090T

AMD goes six core - should the Intel Core i7 be worried?

TechRadar rating:

4 stars

AMD have got their selves into the six core market with an impressive CPU, but if you are looking for a gaming CPU, then Intel still rule this roost

Like:

Six cores for quad core money; Slots into existing motherboards; Excellent number-crunching; Overclocks easily to 4.0GHz

Dislike:

Game performance second to Intel i7 ; Turbo CORE not so clever; No increase in L3 cache for the extra cores; Only dual channel DDR

AMD Phenom II X6 1090T: Overview

At the Pentium 4's press launch, Intel talked confidently about future versions reaching 10GHz.

Oh dear, now we know better. The path to performance lies with multiple core chips. Intel started the trend and where Intel goes, AMD isn't too far behind - and does it cheaper.

On the tail of the Intel Core i7 980X we now have AMD's own six-core offering based on the new Thuban core.

The first two versions are the 1055T running at 2.8GHz, and what we have here: the 1090T, running at 3.2GHz.

The 'T' is for Turbo, AMDs new Turbo CORE technology which boosts performance on selected cores to 3.3 and 3.6Ghz respectively - we'll tell you more about that below.

Now lets get a little technical. What we have here is pretty much a four-core Deneb.

It's made using a 45nm process and each core gets the same 512KB L2 cache, sitting on this is 6MB of L3 cache. There's no extra over the four-core Phenom here, unlike Intel's 980X whose two extra cores come replete with extra L3.

The Thermal Design Power of 125W tells us the limits aren't being stretched excessively, desktop processors have a practical limits of around 140-150W TDP.

The memory controller offers two channel DDR3, rather than Intel's triple channel. Essentially it's simply two extra cores added onto a four-core Phenom, rather than the more comprehensive re-working involved with Intel's six-core Gulftown.

One piece of most welcome news for upgraders is that - for once - a major change in chip doesn't mean new motherboards all round.

The Thuban should slot into existing AM2+ and AM3 motherboards. You'll need to flash your BIOS, but that should be it. If you're running an AMD rig already then you're in for a treat.

This is an important chip for AMD since the four core Phenom doesn't appear to have many more clock cycles left in it and Intel's Core i7 is just so good it has the top of the PC market for itself.

Turbo CORE

All these multiple cores are all well and good but there is an awful lot of code that will insist on just using one core, leaving most of your expensive multi-core chip staring vacantly out the window.

It's all about keeping the total power consumption, and heat, within designed limits. Shut down or throttle back some core and you've more headroom for the remaining cores. Enter Turbo mode.

Turbo 2

THE EASY WAY:Without getting aggressive on any of the settings the chip was quite happy to switch to 3.7GHz - faster than the standard chip in Turbo mode

Intel has its Turbo Boost technology and Thuban brings us AMD's version: Turbo CORE.

Turbo Boost is wonderfully flexible, and can speed up and slow down individual cores and even shut them down completely. Turbo CORE has a less technically accomplished and heavy-handed approach.

If the chip detects that at least three of the cores are loitering with intent it'll kick in and throttle back three cores to as low as 800MHz and boost the remaining cores by a set multiplier. It's either on or off.

Turbo CORE is a welcome and logical addition to AMD's armoury. It's not as flexible or aggressive as Turbo Boost and to be honest at times its difficult to see much obvious difference, given that it switches on and off automatically on the fly. And that the gains are in the order of twelve percent frequency speeds. As with the Core i7, what works better is to push the chip as a whole.

Even more conservative overclocking to 3.7GHz puts you over Turbo mode, and on all cores to boot.

Still, until all software starts using what's on offer some sort of 'turbo' mode doesn't hurt. Overclockers might have more fun here, with the right board you can fiddle with Turbo mode and set it up for specific software to push part of the chip to the max.

Only, well, you've bought a six core chip haven't you? Better to use it all of it.

AMD Phenom II X6 1090T: Performance and overclocking

The first tests we threw at our subject were the x264 encoding and Cinebench rendering tests.

These chuck data at every core as fast as possible and give the pure processing power a chance to shine, and it did, giving quad-core Core i7 a decent rival at last.

Running at its nominal speed of 3.2GHz, both tests beat an Intel Core i7 920, which runs at a little more pedestrian 2.8Ghz, albeit with the healthy advantage of eight threads.

The Cinebench rendering test is particularly impressive. Switch to the overclocked versions and it starts to fall behind a little, here the 920 can be pushed to 4.1Ghz (which is why we like it soooo much).

We were all ready to dip into our big bag of superlatives and start being flowery, when we ran the World in Conflict benchmark. And it is, well, not bad, just not particularly sparkling. Here the Core i7 920 still shows a clean pair of heels and that's why those searchers of gaming prowess still tread a path to Intel's door.

So much for standard speeds, but who wants to stop there? AMD supplied us its Thuban sitting in an ASUS Crosshair IV motherboard. These rather flashy specialist boards are aimed at overclockers and have a bewildering array of tweaks on offer, including an automated overclocking procedure.

Auto oc

AUTO-OVERCLOCK:The ASUS motherboard we were using also has an overdrive utility, which includes an Auto Tuning mode

When we first booted-up it insisted on running the chip at 3.7GHz, and it took delving into the BIOS and setting it manually in the BIOS to get the 1090 running at the speeds advertised. Once benchmarked we began to delve.

AMD supplies its own overclocking utility, OverDrive, to guide your operations. Here you can adjust the multiplier, and base clock as well as an impressive set voltages, timings and frequencies. The advanced settings are just that. At one point it showed we were gunning along at 4.45GHz on all six cores, which had us all excited for a few minutes, but the benchmarks that would run didn't match.

Both the AMD and ASUS overclocking utilities feature automated tuning and both were happy to switch to 3.7GHz. But who can resist manual mode?

We tried various combinations of multipliers and clock speeds and settled on 18x and 222MHz as fast and stable, giving us a whisker under 4GHz. A multiplier of 20x on the standard 200MHz bus also reaches the heady 4GHz milestone.

TurboV

TURBO-V:The ASUS TurboV EVO utility in action: offering a choice between an automated mode and almost too many manual settings

The maximum temperature is quoted as 62 °C, pretty low compared to what a Core i7 can reach. According to the monitoring software we got nowhere near this hot. In fact we barely saw 50 °C, even the full six-core benchmarks were run one after the other and it didn't get ruffled.

If you don't skirt the extremes of overclocking, this is a pretty cool running chip. Given that the Thuban has a 25 per cent larger die size than Deneb, staying to 125W TDP at these speeds is an impressive feat.

Can it go faster? It was tantalisingly close to stable at 4.2GHz. Windows booted as usual and playing around at the desktop reveal no problems, but alas, the benchmarks crashed out soon after starting. We suspect there is more to be had here.

Others more adept at fiddling with esoteric voltage settings should be able to wring a little more out of it. Paying more attention to the Turbo CORE settings could also prove fruitful.

Coupled with an overclocking-friendly board there's some interesting options open here: do run all cores at top speed and forget Turbo mode? Or do you run fewer cores and push the Turbo to the max?

4.4Ghz

4.4 GHZ: Here it is reporting that we are running on a 20x multiplier and 222MHz base clock giving a heady 4.45GHz. It didn't last...

Given that AMD supplies overclocking tools, and that among the first rash of machines sporting the Thuban are some that come ready overclocked to 4.0GHz - why run your 1090T at the boggo standard speed at all? Well quite. Is it some bizarre marketing angle, making you think you've somehow got something for free? Perhaps.

Intel does pretty much the same thing, selling eminently overclockable chips running at sub-optimal speeds. It's a 'feature' - a welcome one undoubtedly, but a slightly odd one nevertheless.

It's not like the old days where such trickery wasn't encouraged and you really felt you'd pulled a fast one and saved money. All this rather begs the question, what can you squeeze out of the cheaper 1055T? That'll be interesting to see. Plus of course these two are just the first Thubans, faster will undoubtedly follow.

Technical analysis

As you might expect, any software that can scale neatly across all six cores does very nicely thank you.

In the x264 and Cinepack tests the 1090T really shines and bares comparison with Intel's lovely Core i7 920, which may have two fewer cores but has two threads per core, giving it effectively eight, plus a 2MB fatter L3 cache. It was overclocked to 4.1Ghz.

The obvious weak spot is the World in Combat test, run at 800 x 600 and low detail and high physics to stress the processor rather than the graphics. Here AMD gives considerable ground to Intel.

The Dirt2 test, run at maximum graphics settings, narrowed the gap and proves its no gaming slouch either. Oddly overclocking here had little effect. No it isn't top dog, but it does have sharp teeth.

AMD Phenom II X6 1090T: Benchmarks

Encoding performance

X264 v2

1090T 28
1090T overclocked 32
i7 920 27
i7 920 overclocked 39

X264 v3

1090T 29.2
1090T overclocked 34.3

Rendering performance

Cinebench R10

1090T 48
1090T overclocked 40
i7 920 55
i7 920 overclocked 37

Cinebench R11

1090T 5.55
1090T overclocked 6.88

Gaming performance

World in Combat

1090T 151
1090T overclocked 169
i7 920 227
i7 920 overclocked 334

Dirt2

1090T 69
1090T overclocked 71
i7 920 80
i7 920 overclocked 100

AMD Phenom II X6 1090T: Verdict

AMD's six-core Thuban turned out to be pretty much what we expected: it's a good value general slogger with some very impressive raw processing power on offer, but as an out and out gaming chip it still comes second to Intel's offerings: the Core i7 still rules the gaming roost.

It's tempting to compare the 1090T Thuban directly with Intel's six-core Core i7 980X. Do this and you'll definitely be disappointed.

It's not nearly as fast in any test, it doesn't have two threads per core or twice the L3 cache for a start so it would have been an amazing feat if it was within striking distance of Intel's finest. It may be AMDs fastest desktop chip yet, but it's not gunning for the top spot.

As ever, price is everything. At £200 a pop it's aimed squarely at the quad-core Core i7s and Core i5s, currently the 1090T is priced directly opposite the Core i7 920. Given that initial prices have a habit of falling rapidly what we have here is another AMD performance bargain.

Only the lack of outright single thread games power, where many games benefit most, makes us hesitate to gush unduly, although if you run your games with the pressure resting on your graphics card the gap narrows.

Unless overclockers can wring something special out of the 1090T, it's merely a worthy and good value chip rather than the new superstar. If you just want six-core goodness for your multi-threaded apps, then it's certainly a proper bargain. For an upgrade an existing AMD system it's a joy.

As in the past, AMD gives you more cores for the money. And you can't complain about value for money can you?

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processors AMD Intel Thuban Phenom
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