AMD A6-3650 £89.98
16th Aug 2011 | 11:02
The cheaper Llano Lynx Accelerated Processing Unit lays it all out
AMD A6-3650: Overview
AMD's flagship model of its new A-Series range of desktop Llano Accelerated Processing Units (APUs) – the AMD A8-3850 – launched last month. At the same time, AMD announced a cheaper, less powerful APU, the A6-3650 – which we have now jammed into our test bench.
If you haven't heard about AMD's Fusion technology before, then the term 'APU' might be a new one to you. The APU is a hybrid chip bringing together both the CPU and GPU and sticking them onto a single die.
Before your eyes glaze over and the moaning starts about integrated graphics being about as much use as a chocolate teapot, hold on, because in the A-Series of APUs, the graphics performance is really rather startling. But more about that later.
This isn't the first incarnation of AMD's Fusion technology, but it is by far the most powerful.
The first Fusion APUs (codenamed Ontario and Zacate, versus the current codename, Lynx) had very low power ratings (Ontario 9W, Zacate 18W). They were aimed at the ultra-thin notebook market where, it has to be said, they didn't exactly set the world alight.
Likewise the first of the Llano chips, the A8-3500M, was aimed at the notebook market, although it made a much more favourable impression this time around.
AMD A6-3650: Specifications and performance
The engineering in AMD's new desktop A-Series is a bit of a tour de force for the design teams, because there's an awful lot going on inside a fairly small package.
Built on a 32nm process, the die of the AMD A6-3650 measures just 228 sq mm, but inside it packs a fully-featured quad core processor, a DirectX 11 GPU and a fully-featured Northbridge with a transistor count of around 1.45 billion.
With all this going on, it's quite some feat to keep the thermal design power (TDP) at just 100W.
To put that into some kind of perspective, a Phenom II X4 940, for example, measures 258 sq mm just as a processor on its own. On the other hand, the Phenom design has something the A6-3650 lacks – namely L3 cache.
The Llano Lynx parts have no L3 cache, and have to make do with just 4MB of L2 cache – 1MB per core. This puts the CPU part of the jigsaw more closely related to the latest Athlon II processors, such as the AMD Athlon II X3 450.
The A6-3650 runs at 2.6GHz out of the box – 300MHz slower than it's more powerful cousin, the A8-3850. And, like the A8-3850, it lacks the Turbo Core, although this will be part of the other two A-Series APUs that have yet to make an appearance – the A8-3800 and the A6-3600.
These chips have slower clock speeds, of 2.7/2.4GHz and 2.4/2.1GHz, respectively, but come with a TDP of just 65W.
When it comes to the graphics core, the A6-3650 uses the slower AMD Radeon 6530D chip compared to the A8's Radeon HD 6550D.
The HD 6550D is comparable to the discrete AMD Radeon HD 5570, while the HD 6530D is more like an AMD Radeon HD 5550, with a core speed of 443MHz, 320 Radeon Cores (AMD now calls the unified shaders Radeon Cores, in much the same way as Nvidia's labelled its CUDA Cores), 16 texture units and eight ROPs.
All of which means that the HD 6530D can deliver around 284 gigaflops of graphical processing power.
This may be a lot lower than the A8's 480 gigaflops but it still dwarfs Intel's HD 3000, which can only summon up a mere 125 gigaflops.
Oh yes, and the Intel part is only DirectX 10.1.
AMD A6-3650: Benchmarks
If you are used to integrated graphics stuttering along with single figure frame rates in most things you test them with, then the GPU in the new Lynx APU's will come as a bit of a shock.
Add in a value end card like the AMD Radeon HD6670 for dual graphics and you have some highly playable frame rates.
AMD A6-3650: Verdict
The one thing that really stands out with the AMD A6-3650 is its overclocking ability, particularly at its price point.
We were able to get our review sample to 3.04GHz (117MHz x 26) without any problems and without resorting to tinkering with any other settings in the Bios. Adjustments to the APU voltage settings should see it go much faster, but even so that's a 400MHz+ increase over the stock speed.
Of course it's not only the CPU part of the AMD A6-3650 die that's overclockable – the GPU is too.
You can go from the 443MHz of the HD 6530D up to the 600MHz that is the stock speed of the HD 6550D in the A8-3850, without any problems and with complete stability.
That sort of overclocking, however, is always going to be dependant on the particular slice of silicon in your machine.
It's also good to report that finally after all these years we have integrated graphics that actually offer some decent frame rates. Once you've recovered from that shock bit of news, the other point to take note of is that the GPU also supports DirectX 11.
Sadly, both the decent frame rates and the DirectX 11 support are not available with Intel's latest HD 3000 graphics – those of Sandy Bridge fame – so extra brownie points to AMD then.
There is also the added advantage that you can chuck in a cheapish discrete AMD graphics card, and by enabling the dual graphic mode you can achieve some very playable frame rates.
We did have a couple of odd moments during testing when using a graphics card in dual mode with the integrated graphics where the screen would go blank so you didn't quite know where you were in the boot cycle. Then suddenly it would wake up to show you that the OS had loaded fine, but on a couple of occasions we lost patience and rebooted.
This was probably due to the immaturity of some of the motherboard drivers, and was annoying rather than alarming.
The only other thing of concern is the longevity of the platform itself.
With Bulldozer and the Bulldozer-based APU, Trinity, fast approaching on the horizon, the worry is that the FM1 socket will be here today and gone tomorrow. Remember what happened with Intel's Socket 1156 when the new Sandy Bridge technology appeared?
Getting one of these new APU's isn't quite the future proofing move it might appear to be at first glance then.
There's no doubt about it, with these new Lynx desktop chips, AMD has seriously upped the ante when it comes to integrated graphics performance, especially at the price the A6-3650's been pitched at.
The dual graphics option is also interesting, because it allows for some fairly intensive gameplay without having to break the bank for the discrete graphics card.
One of the nice surprises of the APU is its ease of overclocking and how far it will go without having to get your hands too dirty in the Bios.
Another plus point is its support of both the latest JEDEC memory frequency standards over and above the 1,333MHz base point, at 1,600MHz and 1,866MHz.
Aside from the slightly immature drivers around at the moment, there is a worry that the FM1 socket won't be around for very long.
We were impressed with the AMD A8-3850, and similarly the cheaper A6-3650 doesn't disappoint either