If it were me and I was building an AMD64 machine right now, I would buy OCZ. I have read many reviews on many sites, and the fastest OC was on anadtech.com and it was done with OCZ PC3700 Enhanced Bandwidth. It was faster then even 4000 and 4200 memory on an Intel machine. I think they got the FSB up to or close to 300 (600 at DDR) which is astonishing. Not only that, but they had 2.5-2-2-5 timings still at that speed, that is downright phenominal and is unmatched with any other memory I have seen. For some reason that OCZ EB series stuff just flies with the AMD64. Anandtech says that most athlon 64 motherboards are just picky with memory. Here I found a article where they were talking about it. Now I just need to find the guide where they were testing it.
Originally Posted by Anandtech.com
The EB takes a little different approach to memory timings, and runs at 2.5-2-2 at DDR400. This is still competitive with the best memory available, but by DDR433 to DDR450, the EB becomes the fastest memory that we have tested at that speed. Performance extends well beyond DDR500 and the performance at DDR500 is the best that we have tested. Many Athlon 64 boards are picky about memory, but every Athlon 64 board that we have tested so far seems quite content with either 3700EB or 3500EB memory.