Does the memory run ok at 1066 at standard settings?
I would see what the memory will do on the board at both 1:1 fsb..using a 2.00 multiplier and using 2.4 multipliers and maybe a 7x cpu multiplier.
Then see what the cpu will do with the memory underclocked..
Running the memory at lower than its rated speed wont decrease performance if you can tighten the timings and increase the fsb.
Initially I found .up to about 450 fsb was no real problem .After that a lot more tweaking at setting ref v's was involved.
cpu speed of 3.9-4ghx ..1.37-1.4v.. perhaps..then 3.8 maybe only 1.32.
4 sticks complicates things.I only had 2 at very high clocks 4 sticks got much lower speeds but one set was only rated for 667 mhz.
OOh found an old thread :)
EP45 UD3 and cheap?5300(667mhz) memory testing
This is the one I usually put up.
Kind of an old thread too.
775 quads and duals at hi fsb on ep-45 ud3
check my disclaimers..
Im not "full overclocking" mine anymore..but no doubt PJim or other experienced ep 45 tweakers will post. Not much action on it now.
Did you look thru this thread?
Overclock Q6600 on GA-EP45-UD3P + 8GB DDR2 800MHZ RAM