Memory performance

Our 790GX platform has slightly more memory bandwidth than the 750a when both are running their integrated graphics, but the tables turn when we swap in a discrete graphics card. Of course, both chipsets are sharing the same on-die Phenom memory controller here.

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

Little changes when we move up to four DIMMs.

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.

When you're running the same Phenom memory controller paired with the same memory running at identical timings, there isn't a whole lot of variety in memory access latency.