This article sums up and adds to three memory scaling articles that we've published in recent weeks:
DDR3 Memory Scaling on AMD’s Phenom II X4
Core i7 Memory Scaling: From DDR3-800 to DDR3-1600
DDR3 Memory Scaling on Core 2 Quad
In all three cases, we used the same benchmarks and cross-tested the systems with memory speeds from DDR3-800 to DDR3-1600, applying both relaxed and tight timings. The purpose was to take popular memory configurations and show their effective performance levels. In each case, we also added a benchmark run that shows the impact of increasing the processor clock speed instead of investing in high-end memory.
In general, the benefit of expensive enthusiast memory is at least questionable. We found that tight timings are typically more beneficial than high memory clock speeds. But in the end, it’s important to look at the benchmarks that are relevant to you.
This picture story compares the performance benefits of using faster DDR3 memory across all three popular platforms: AMD’s Phenom II X4 955 (3.2 GHz), Intel’s Core 2 Extreme QX9770 (3.2 GHz), and the Intel Core i7-975 (3.33 GHz), which is Intel’s current flagship solution for enthusiasts and professionals.
We wanted to know how much each of these three architectures can benefit from faster memory. Which platform benefits more, and where might high-end memory be negligible? Let’s find out. The following results show DDR3-1600 performance with quick CL8 timings normalized to DDR3-1066, which equals 100%.
Please note that the results list Intel's Core i7 at 3.47 GHz. We manually set the clock speed to this level to get consistent results, as Intel’s Turbo mode would automatically overclock individual cores to this speed under heavy processing loads.