Pardon the obnoxious title of this post, but here is something I want to share, and I feel it is necessary to disperse some absurd ideas going around.

Intel's next generation Sandy Bridge microarchitecture features an integrated graphics core: the CPU and GPU share the same die. The GPU will have up to 12 dual-issue execution units (EUs) [Anandtech]. In terms of maximum theoretical computing performance, an EU is equivalent to two stream cores (AMD) or two streaming processor (Nvidia), because contrary to AMD and Nvidia, it is dual-issue, therefore can execute 2 instructions per cycle. It is unclear what the frequency clock of the EUs will be, the same as the CPU cores (~3GHz), or closer to AMD's and Nvidia's clocks (~1GHz), or somewhere in-between. Let us assume 2GHz.

2 instructions per clock (dual-issue EU)

times 12 (number of EUs)

times 2 billion (2GHz)

equal 48 billion instructions per second

This number of instructions/sec gives an idea of the level of performance of a GPU (graphics operations are translated to GPU instructions, and execution units occupy most of the area of a GPU die). For reference a low-end AMD Radeon HD 5450 can execute 52 billion instructions/sec . Very close. In fact, this exclusive preview of a Sandy Bridge Core i5-2400 3.1GHz confirms that the performance of the i5-2400 matches roughly the performance of the HD 5450, which shows the math is right.

Ready for the kicker?

The highest-end AMD Radeon HD 5970 can execute 2320 billion instructions/sec . In other words a ~3GHz Sandy Bridge processor's integrated GPU will deliver only ~2% of the graphics performance of the highest-end AMD Radeon video card.

Do not misinterpret me. 2% may sound bad, but it is good enough for entry-level graphics performance (or else AMD would not be selling the HD 5450). My point is that by their own design, Intel obviously do not intend to, and will not compete with top-of-the-line discrete GPUs. Nonetheless, 12 EUs seems really low; this number was probably carefully chosen so as to not unnecessarily waste die space and power.

That said, perhaps Intel were originally hoping their integrated GPU would be fast enough for some high-definition video transcoding, and after realizing it would not be the case, set out to design the Media Engine, aka Display Engine. This is a separate block on the die, neither part of the GPU, nor part of the CPU cores, but part of the "System Agent", and is made of fixed functions to implement video encoding and decoding as efficiently as possible.

In conclusion, I am looking forward to play with Sandy Bridge, but not for high-end GPGPU or gaming :-)