Memory Bottleneck - Help

I'm in the middle of attempting to get the max overclock out of all my new components, and I've run into a brick wall with RAM speed.

The CPU seems rock solid and will plod along just fine around 3.2ghz at 1.35v.

The RAM OTOH isn't fond of speeds > 450mhz or so. I've cranked the voltage up to 2.6v and managed to hit 466mhz stable (so far), but I'm worried the excessive voltage isn't good for things. I've tried reducing timings, it still won't post at the higher speeds. I can increase voltage to 3.1v on this board, but how much voltage is too much?

The RAM is the G.Skill that's reviewed on Anandtech, it supposedly has lower-binned Micron such and such a chip that they've clocked all the way up to DDR2-1067. I'm aiming to go higher on the FSB and clock both the processor and RAM a bit higher, even if it means I have to reduce RAM timings somewhat.

I'm certain it's the RAM because at 466fsb, it will post and boot windows at 2.6V, but will not POST at 2.5v.

Any help would be greatly appreciated.

Whoa!! 2.6v??? Thats pretty huge! I won't run my dominators at 2.3!! Anything above 2.4 is asking for trouble unless they are "very nice" (hint: expensive/high quality) memory pretty much MADE to do that...

You reduced the timings and it won't post? Thats strange, did you try 5-5-5-15? Also, have 4 sticks is probably hurting you, I'd remove the 1gig set so you have 2x1gig...)

Yes 2.6v is very high and they won't be lasting long!! I'd suggest either selling them and getting some higher frequency chips or settle with you have and burn them into the ground

Okay, I've reduced the voltage down to 2.4v, and it's rock solid at 3.13ghz and DDR2-894.

What boggles me is that the system is stable past 447mhz FSB, but when I go 448mhz and higher, my RAM bandwidth efficiency as reported in Sandra goes from around 53% to 43%, and kills my scores without me changing any RAM timings. Any explanation for this?

Also I can run the RAM at 1:1.2 stable, which puts it around DDR2-1110 at 5-5-5-15, but again the bandwidth efficiency goes down to around 40-45% and scores much worse than when it's set to DDR2-894, 4-4-4-9.

Thanks again for the help.