Overclocking on the ASUS P5K3 motherboard proved to be interesting. To start overclocking I kept the FSB the same and tried to see just how tight I could get the timings to see what I could get. At the stock voltage of 2.0V, the system was unable to post with a command rate of 1T, but with a voltage increase on the memory 1T was easily reached.
With the voltage cranked up to 2.25V on the memory modules I was able to take the timings from 7-7-7-20 2T to a more impressive 7-6-5-16 1T with ease. This was the tightest I could get the timings on the kit at 1800MHz. When I tried to lower the RAS to CAS Delay to 5 or the CAS Latency to 6 the system would post, but would blue screen on the Windows XP splash screen. One thing I found interesting is that for those of you interested in playing with tRCD and tRP the vast majority of 1800C7DF and 1600C7DHX memory kits should allow to tighten those timings to tRCD=6 and tRP=6 without a voltage bump. Corsair decided not to rate these timings this low, but that doesn’t mean you can’t.
Now that we know how tight we can get the timings the next step it to find the max of the memory kit. While I had hoped to reach 2GHz on this kit my hopes were soon dashed by my Intel Core 2 Duo E6750 processor as it tops out at 480MHz no matter what board, multiplier, voltage or BIOS settings I throw at it. I guess I can’t complain about a 2.66GHz processor being able to overclock to just 3.84GHz, but it sucks that it is holding me back with this memory kit. Even with this limitation I was able to bring the Corsair DOMINATOR 1800MHz C7 kit to 1920MHz with 7-6-6-20 1T timings!
The best Sisoftware Sandra XI SP4a benchmark score that I was able to pull off was just shy of 10,000MB/Sec, which was done at 7-6-6-18 1T timings at 1916MHz.