Then there's Microsoft's DirectCompute, which was released as part of DirectX 11, and so is installed on pretty much every recent Windows PC. It's this latter standard that should at last bring GPU-acceleration to the most PC users, much as DirectX has for PC gaming since the 1990s.
All Fusion hardware will support these two standards, and will have an architecture designed to maximise the strengths of a general purpose CPU and a parallel-optimised GPU. Each Fusion APU will have processor and graphics cores, often multiple examples of each, on the same processor die. This will allow both to access the same high-speed cache and so more effectively blend these complementary types of processing power.
It's worth emphasising that Intel's Sandy Bridge chips (or the 2nd Generation Intel Core Processor Family as they're officially known), already integrate graphics and CPU in this way. However, at present Intel's graphics technology lags behind AMD's, most notably in its lack of support for DirectX 11 and thus DirectCompute.
There's a reason we've yet to talk about specific products - there's still very little Fusion hardware available. We've only seen a couple of motherboards with integrated APUs and a few upcoming netbooks. These are direct competitors for Intel's established Atom range, currently ubiquitous in low-power desktops and netbooks.
AMD's Fusion upstart has a confusing barrage of codenames - it's the Brazos platform, using a Hudson chipset, and a Zacate E-series APU. The E-350 APU we've tested contains two processing cores, codenamed Bobcat, which each run at a modest 1.6GHz and have a pair of 512KB caches. It scored 32 overall in our applications benchmarks, a touch quicker than Intel's dual-core Atom D525 which scored 28. Also present is an AMD Radeon HD 6310 graphics core. In our tests this scored only 7.3fps on our desktop Call of Duty 4 gaming test, but then it's not designed for such use, plus the Atom's graphics chip can't run this test at all at our preferred settings.
