DDR2 @ 5.5.5.15 900Mhz or 4.4.4.12 800Mhz

[BTRY B 529th FA BN]

So, with this new board comes new findings. My recently stable 1000Mhz sticks are now failing by Memtest HCI (very good test btw) Why my other board didn't find this makes me wonder. I am not about to go out and buy a DDR2 kit for 179$ - hell no! haha. So, I've decided to just work with what will run stable as I am stability testing my ram now. I had it running at 450fsb 1:1 = 900Mhz 5.5.5.15 (tested with a low 6x multi) Managed to pull over 160% until i stopped HCI. Now I am testing 400fsb 1:1 @ 4.4.4.12 and it's doing well also. The thing is they both need ~ 2.08v The good thing is I know I have headroom for my Q9550 to potentially hit 3.825Ghz which is moderatly high while I am searching for a moderate to mild overclock of 3.6Ghz or < While I konw timings and speed don't matter much with an i7 what is better on a 775lga quad?

 

[EarthwormJim]

I personally would rather run at 400fsb since you'll need less voltage to do that anyway, specifically PLL voltage. 45nm chips are supposed to be sensitive to PLL voltage.

You'll be able to pick a lower performance level too (tRD I believe).

A CAS setting of 4 @800mhz should result in lower latencies than a CAS setting of 5@900mhz.

CAS4 @800mhz: 4/(800E6) = 5ns
CAS5 @900mhz: 5/(900E6) = 5.55ns

I think latencies are more important than sheer bandwidth on LGA775 systems. If you look at the older Anandtech reviews, they were getting tons of bandwidth at only 400mhz FSB.