Memory subsystem performance

Right off the bat, we see that the simulated 940's faster L3 cache and memory controller speed can make a difference. The retail 940 scores almost identically to the Core i7-920, which shares its 2.13GHz L3 and memory controller clocks.

There's not much separation here overall, but look closely at the 4MB block size. This is right where the L3 cache on the Core i7 will be getting a workout, and the bandwidth difference between the two 940s is substantial: 55 GB/s for the simulated part, and 37 GB/s for the real deal.

Since it's even more difficult to see the results once we get into main memory, let's take a closer look at the 256MB block size:

In this test, once main memory becomes the limiting factor, the simulated and retail 940s perform the same.

Memory access latency is another story, though. The simulated 940 shaves eight nanoseconds off the access time of the real thing, a fact that could have real-world performance implications.