Phenom II 940 and 8gb at 1066 why not?

[Giannone]

I have a motherboard Asus M4A79 deluxe m2+ with a Phenom II 940 and 4x2gb Corsair XMS2 8500cl5 1066mhz that works only at 800, if I try to set timing the mother board recognize them correctly but the sistem became instable, prima95 errorafter 2 min.Wat I should do?
Sorry for my English but I am from Italy
Gian

 

[jitpublisher]

Try setting the voltage and timings to this manually.
If that does not work, raise the voltage slightly, like to 1.92~1.93, but do not go over 1.95.
1.9v 5-5-5-12 and 2T

 

[Giannone]

Ty, but why you said not over the 1.95v And why 5 5 5 12 because Corsair said:

Tested at latency settings (5-5-5-15-2T) at 2.1V
at 1066MHz
SPD programmed at:
JEDEC standard 5-5-5-18 values at 800MHz
EPP standard 5-5-5-15-2T, 2.1V values

Do you know that thereare some problems with this CPU and or Motherboard and this Ram? Asus on the manual said that 8gb at 1066 will be recognize due to the CPU limitation at only 800mgz. but I know that some other overclocker use them. I think You are right about sdram voltage an I'll try, do you think that Cool'n'Quiet option could be on or will be better disable?
thank's again yo are the first one that give me an usefull help from both part of the seas
big hug
Giannone

 

[jitpublisher]

Ah, I thought that RAM ran at 1.9, but if it says 2.1, that is where it needs to be.
Also, the statement about the chipset limitation means something.....
Anyways, after all is said and done, you will not notice any difference in the speed of your memory whether it is at 800 or 1066.
Try taking out 2 of the sticks, see if it then boots and runs a 1066.
If it does, I would say the limitation noted about the chipset has been found out for certain.