Ryan from OCZ let us know they've been testing out their new PC4000 sticks and they've been able to hit 290MHz with increased voltage mods. Without any drastic voltage mods, they were able to get 285MHz (570MHz DDR) out of their PC4000 with a Canterwood-based ASUS P4C800 motherboard.

 

I just though everyone would like to see our progress on achieving DDR566 and above speeds ,we have been running up to 580Mhz with increased VDIMM voltage. These benchmarks were taken with the OCZ Gold 4000 1 GB kit on the ASUS P4C800 ,instead of releasing a DDR 533 or 566 product we will for the time being be using these extremely fast IC's in our gold PC-4000 kits to increase the value of our products to the end user.

Unbuffered SiSoft Sandra Benchmarks @ OCZ Technology