OCZ PC2-4200 Rev.2 and ASUS P5AD2-E
 

We finally tried to figure out the maximum stable frequency for our DDR2 sticks. We could push the OCZ to 674 MHz with latency timings of 3-2-2-2 while CPU and memory were running synchronously at 1:1. This gave us a bandwidth of around 7300 MB/sec in Sandra, the best result we achieved in our test. After reducing the timings to 4-3-3-8 and running CPU and RAM asynchronously at 3:4 we could push the frequency up to 814 MHz.

http://www.overclockers.com.au/article.php?id=340589