overclocking q6600, weird memory instability

[johang]

im trying to get my q6600 g0 stable my problem is that on 320 x 9= 2.88ghz with memory in 1:1 (640) ratio is stable but as soon as i go up to 340 with memory at 680 prime95 fails blend and large fft test. my memory is ddr2-800 cl5 so it should handle that easily. if you push to 400x8 = 3.2ghz with memory on 800 with 5,5,5,15 timings then its more stable but not 100% . it seems that as soon as you go past 667 it boms out.

any help please

q6600 g0
biostar p965pt mobo
2 x 1gb ddr2-800
600w coolermaster igreen psu
lots of cooling

 

[richardscott]

run ure mem in linked sync mode for extra stabilty

 

[johang]

they are. i said my memory is in a 1:1 ratio with my fsb. thats why 320 fsb gives me 640 on my memory

 

[PlasticSashimi]

I run mine unlinked, it alowed me to test more settings and my benchmarks tell me 1:1 isn't always a big deal.

just try for some kind of reasonable ratio

 

[PlasticSashimi]

oops

 

[johang]

weird i changed the module from dimm 0 to 3 and the one in 2 to 1, swapped banks and order and bobs your uncle, looks stable so far gotta run tests

 

[Mondoman]

Have you set the RAM/DIMM voltage to the manufacturer's spec (which is often higher than the 1.8V DDR2 standard)?

 

[johang]

the manufactures website says JEDEC standard 1.8v + 0.1v and VDDQ same voltage

 

[Mugz]

Give it 2.0V.

 

[Mondoman]

the manufactures website says JEDEC standard 1.8v + 0.1v and VDDQ same voltage

Are they saying that your specific RAM model number uses a 1.8V spec, or that the JEDEC standard uses a 1.8V spec?
What brand and model number RAM are you using?

 

[johang]

2 x 1gb transcend jetram ddr2-800 cl5