Well, I've been fighting these 4 sticks of RAM ever since I stuck them in this motherboard. Every single time I though they were stable....they weren't. For instance I could set the timings to 5-5-5-15 2T @ 667 and run Memtest for 6+hrs with no errors....reboot and try to boot Vista..Nope...BSOD. W-T-F. Odd thing is that sometimes Vista would boot fine and other times it would not....and I could run Nvidia's memory stability test for hours.... Mabye the voltage going to all 4 memory slots isn't steady? That's the only thing I can figure because tonight I ripped out 2 sticks and I was able to bump the memory up to 825mhz with an FSB of 1650mhz and processor speed of 3300mhz (8x multiplier) at 4-4-4-12-2T timings!. Crazy.
Currently running an Nvidia stability test in Vista since Memtest doesn't seem to be doing a damn thing whereas with Vista I could immediately tell when it didn't like the memory. I don't know if it's the motherboard or the OS but I've never had this much luck with overclocking and Windows OS's. Seriously this is crazy. I must have BSOD'd vista like 50+ times, Read memory errors in Vista, Hangs in Vista, heck my last try before I left 2 sticks in there I couldn't even load the Vista Boot menu because it said the files were corrupted. (Memory problem again)....yet it still boots and the registry never got corrupted.
I think I'll stick it out with "only" 2gb of memory until the end of this year (unless I get anxious....which I probably will) and then upgrade to a bearlake level chipset with DDR3.....although I highly doubt 4gb of DDR3 memory will be very cheap even at the end of the year....
From the benchmarks I've seen DDR2 performs the same as DDR3 on the new chipsets right now (better memory controller), I guess we'll see how fast DDR3 really gets later this year/early next year.