Overclocking
OverclockingBefore attempting overclocking, I tried to run the modules with tighter latencies. After all, reducing latencies increases performance. Unfortunately, running at 3-3-3-8 proved impossible, even with 2v. I wonder how Corsair attributes its XMS moniker for RAM. Surely they must run at higher speeds/lower latencies than average, generic modules?. Corsair specifies 4-4-4-12 latencies for this Twin2X pair, the same as every other manufacturer's DDR2 modules. For example, Crucial and Samsung both market the identical RAM with respect to speed and timings.
Overclocking was undertaken by raising the CPU's FSB. This, in turn, raised memory frequency by a ratio of 3:4. Such that a CPU FSB frequency of 220MHz would result in DDR running at 293MHz (effective 586MHz).
Keeping the default 4-4-4-12 timings, I managed an overclocked, effective speed of 600MHz. It was achieved by running the pre-described 3:4 FSB-to-RAM ratio with FSB set to 225MHz. Further, the multiplier was dropped down to 16x, giving the following setup:
3600MHz CPU (16x multiplier) - 225MHz FSB - Corsair DDR2 Twin2X @ DDR600 (4-4-4-12)
UT2003's low-detail test was re-run to see the effects of a faster FSB coupled with faster RAM.
Given an identical CPU speed, an increase in FSB and RAM speed brings out meaningful gains in performance. We can expect similar non-CPU-related gains when Intel steps up its Prescott's FSB later this year. However good the overclocked FSB and memory looks in comparison to default settings, one must remember that an Athlon 64 Model 3800+, paired with low-latency DDR memory, hits over 200FPS in this benchmark. Performance increases are all relative.