Let’s resort to benchmarks estimating the “real” performance.
3DMark results are not impressive; as we have already seen, this test barely reacts to memory subsystem parameters. However, CustomPC Benchmark shows that in real, mostly multi-task scenarios, fast DDR3-1600 with 7-7-7-20 timings may provide a pretty significant performance improvement. The performance may increase by up to 10%, while the total score reported by the benchmark shows almost 3% advantages of the system with DDR3-1600 SDRAM.
High-speed memory is also great for contemporary games. Even DDR3-1600 with “weak” timings of 9-9-9-27 works a little faster than DDR2 SDRAM. More widely spread faster DDR3-1600 with 7-7-7-20 timings provides a tangible fps advantage. Note that with higher processor bus frequency the value of fast memory also increases. And although at 400MHz FSB the performance gain was more of a symbolic nature, then at 500MHz FSB it reached 5%.