KitGuru spent the day with AMD in Berlin, learning about the latest addition to their Fusion APU range, the A-Series. There was a lot of hype surrounding Fusion when it launched back in January. We tested some products based on the E-Series Fusion platform and were left with generally positive impressions.
The existing E-Series platform is designed for small form-factor desktops and laptops, providing a low cost, low power solution that is able to deliver high definition content. With the A-Series, though, AMD have stepped up the performance as it is designed for use in mainstream notebooks and desktops.
Fusion is essentially a multi-core CPU and a discrete-class GPU on the same piece of silicon. AMD also integrates the northbridge into their fusion chips, decreasing the number of supporting components that are required on the motherboard.
Having a CPU and GPU on the same chip isn’t anything new, though, as Intel combine both with their Sandy Bridge offerings. The difference is that AMD assign a lot more of the transistors to the GPU portion of the chip so that the CPU and GPU parts occupy approximately half each.
The APU requires a Southbridge for I/O connectivity which AMD have renamed the “Fusion Controller Hub” or “FCH”. There are two models of this available, the A70M and A60M. The only difference between the two is the inclusion of USB3.0 support on the A70M. They support all the latest interfaces including DisplayPort, HDMI and SATA 6 Gbps.
There isn’t anything groundbreaking about the technology that AMD are putting into these Fusion chips. The CPU architecture is based heavily on that of the current Phenom II X4 chips with a few tweaks here and there. This includes shrinking the manufacturing process to 32nm and ditching the L3 cache to make room for all four cores on the chip. They have doubled the amount of L2 cache to 1 MB per core, though, to help make up for this.
The graphics portion of the chip is also based on existing technology and shares a lot in common with the HD 5500 graphics series. On the top-end chips, this is based on a HD 5570 with 400 graphics cores. This should provide a lot more graphics performance than Intel’s HD 3000 graphics which can’t cope with most games and are only good for general productivity and media. The graphics cores also support OpenCL giving a performance boost in supported applications.
For those who demand a little more graphics performance, you can add a discrete graphics card alongside the Fusion APU in dual graphics mode. This is essentially a form of CrossFire which lets the system share rendering duties between the inbuilt GPU and the discrete GPU to boost performance. AMD have come up with a system for branding dual-GPU based systems which is outlined above. The ‘G2′ suffix indicates the presence of two cards in the system.
Unfortunately, the Llano APUs aren’t backwards compatible with socket AM3 and AM3+ motherboards, meaning you’ll have to wait for Bulldozer to upgrade. But considering that the A-Series APUs are going to offer a similar level of performance to the outgoing Phenom II chips, there wouldn’t be much point in upgrading.
The CPU and GPU portions of the APU share the DDR3 system memory, with the GPU portion getting priority over memory bandwidth. This is quite important as the GPU portion will occupy a lot more bandwidth than the CPU, especially in graphically-intensive tasks.
One of the main challenges in integrating the CPU and GPU into a single chip is keeping the TDP capped to a sensible level which isn’t going to drain too much power or produce too much heat. To achieve the best possible performance-per-watt from their APUs, AMD have employed some clever power gating technology which is able to shut down individual cores when they are not required so they don’t consume any power. They are also able to boost the performance of one part of the chip when another isn’t being used, making use of the full TDP.
With the A-Series APUs AMD are claiming that notebooks will be able to have an all day battery life. For those of you who are getting your hopes up, this doesn’t mean that they will last for 24 hours, though. But they do say that we can expect a resting battery life of up to 11 hours. Of course the actual battery life of a system will depend on numerous factors which will be specific to certain models meaning we can’t give you a more specific idea of battery life without testing some A-Series notebooks ourselves.
So where did AMD pluck the 11-hour figure from? Well they compared two similarly configured notebooks, one with the AMD Vision A8-3500M APU and one with the Intel Core-i7 2620M CPU, using the integrated graphics. In the resting test, the Intel machine ran out of juice at around eight hours while the AMD one powered through to eleven. In the 3DMark Vantage test, the AMD system lasted for 2 hours and 48 minutes while the Intel system could only muster enough power for 1 hour and 46 minutes. There are a number of reasons why the power consumption is much better, for example, the APU is able to switch off different parts of the chip when they are not being used so they don’t waste unnecessary power.
Even though energy efficiency is one of the main features of the A-Series APUs, KitGuru is also interested in the performance that they are able to deliver in game and in general productivity situations.
We were very surprised at how well the APU coped with gaming. AMD let us play with an MSI laptop which featured an APU on it’s own (we’re not quite sure which model). When playing Dirt 3, the machine achieved a playable framerate when using a resolution of 1080P at medium settings. This is truly amazing when you consider how an Intel’s HD3000 integrated graphics would perform (or wouldn’t) at this settings.
For people who want a bit more gaming horsepower, AMD were showcasing a number of machines which have a discrete GPU in addition to the APU chip. Unfortunately we weren’t able to do a direct comparison ourselves with an APU only machine but AMD claim performance improvements of up to 75%.
Here is a comparison chart of all the APUs that AMD are currently offering, outlining the clock speeds of each APU for the CPU and GPU cores.
AMD are clear about which Intel product they are targeting with their APU range which is outlined in the diagram above, with an emphasis on targeting Intel’s Core i3 CPUs with their A6 Series. Even if the A6 can’t offer quite the same raw processing power as Intel’s i3 chips, the graphics power may swing customers away thanks to the better gaming and media performance.
KitGuru says: We look forward to putting the A-Series APUs through their paces in our labs to see what level of performance they are really capable of.
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