Quote - You can use the cpu-z program I posted a link to and find out what your memory is running at. It works for intel and amd.

I'm running a 1:1 ratio on the bus and memory.  400 on the bus and 800 on the memory. Timings are pretty loose at 5:5:5:15. I was running it at 1066 with the same timings but got intermittent crashes about once a month. Tried 5:5:5:18 and still wasnt stable.  My multiplier is set at 9. The memory is rated at 4:4:4:12 800mhz.

 My DRAM Freq is 680 MHz, with a 3:8 multi (255 MHz Frontside bus).  Timings are 7:7:7:24, but DDR3 doesn't have as good a latency as DDR2.

Quote - I'm using the p5q pro turbo motherboard and for quads it doesnt like to go over 460 on the bus.

Mine gets cranky over 260.  And yet somehow I had it running at 275 for a few weeks just fine, I just can't remember now how I did it lol.

Quote - Tomorrow I will get the q6600 up to 4ghz and tighten the timings for the memory, then run the benchmark. I've had it up to 4.1ghz but vcore was getting kindof high along with temps. I'm using the cm v6gt for cooling but it still likes to run hot

Remember the Q6600 is the older 65nm technology instead of the 45nm for newer 775 socket cpus.

For some reason I was thinking mine was 65nm too, but it's 45nm.  Maybe that's the difference.