Memory performance

Even sharing the same integrated Phenom memory controller and identical memory timings, there's a slight difference in memory bandwidth between our 790FX and 780a boards. The nForce pulls up a little short, but since the memory controller is located on the processor die, that's more a knock on Asus' memory controller tuning than on the 780a chipset.

Memory controllers don't always handle four DIMMs gracefully, so we popped an additional two memory modules into each system for another round of tests.

Our 790FX board extends its bandwidth lead over the 780a with four DIMMs installed, and it steals a win in the latency test. MSI has had more time to tweak the memory performance of its 790FX board, though, and I suspect Asus' 780a will catch up in a BIOS revision or two.

The following latency graphs are a little indulgent, so I won't be offended if you skip them. They show access latencies across multiple block and step sizes, painting a fuller picture of memory controller performance with each chipset. Yellow represents L1 cache, light orange is L2, red is L3, and dark orange is main memory.

Same integrated Phenom memory controller, same access latency picture. Moving along...