I already mentioned it earlier, an integrated GPU will not perform as well as a discrete card with the same specs, because of the sharing of system memory between CPU and GPU, where a discrete card has dedicated memory and a dedicated memory controller.
Today, the first (p)reviews of production Llano chips have surfaced. Indeed, based on the specs, you would expect Llano with 400 stream processors at 600 MHz to be roughly as fast as the Radeon 5570 with 400 stream processors at 650 MHz. We see from the benchmarks that this is not quite the case. We also see that the memory speed has a huge impact on graphics performance. There’s a very significant difference between ‘standard’ 1333 MHz DDR3, and high-performance 1866 MHz DDR3 memory.
So while the performance is very impressive for an IGP, it is not quite the threat to discrete videocards that some people thought it would be. A Radeon 5570 in itself is not quite a great gaming card. There is still a huge gap with the more serious discrete cards on the market. And the Fusion GPU is not even as fast as that one. If you’re into more serious gaming (or other types of graphics processing), you will probably be using a discrete card for a while yet.
The CPU-side is not that spectacular either. It is basically just an Athlon II X4 processor. The GPU took up quite a large part of the die, much more than with Intel’s Sandy Bridge. So in a way, what you gain in GPU performance, you lose in CPU performance. There’s no such thing as a free lunch.