Sorry I have been out of the loop for a very long time. I have a donated build that I need to finish. The processor is a E8400 Wolfdale running on a Gigabyte board with P43 chipset that supports 1066. Since 6400 ram is still relativity cheap compared to 8500. How much of a performance loss am I going to see running 6400 over 8500 with the E8400.