Can't run Crucial CL2 memory at 2/2/2 5/7??

[Shag]

I just received 2 128meg CL2 crucial 7.5ns DIMMs from buy.com ($138 total after coupon and gc 🙂 ). I popped them into my CUSL2, set the memory timings to 2/2/2 5/7 and rebooted. The pc froze while detecting plug and play devices every time I tried to boot at these settings. Set the timing back to 7/9 and it worked fine. Why is this? Shouldn't this memory be able to run 2/2/2 5/7?

 

[dakost]

I'm not sure why, but there was a review - head on test between Micron and Mushkin rev 2 some time ago and the guy who tested them mentions that even the 7 ns Mushkin memory couldn't run at 5/7 timings, so extrapolating, the Micron shouldn't do so as well. Unfortunately i don't remember where i read this.
I have micron pc-133 cas 3 memory and amazingly it will run as cas 2 up to 141 fsb, after this benchmarks like 3DMark200 fail, and i can't run on 5/7 timings as well, even at 133 fsb. Moreover, before i bought the cusl2 i downloaded the manual fron the asus site and i do remember that the first manual specified the memort timing options as 6/8 and 7/9. I even e-mailed Asus asking why they have changed this, but i never got a reply.

 

[roc919]

What is the 5/7 and 7/9 timing?

 

[divinemartyr]

Shag,

I have the same setup as you and could not run 5/7 timings EXCEPT for at 133 fsb. Anything higher than this I had to run at 7/9. I'm currently running at 133mhz fsb 5/7 2-2-2 timings. I also only have one dimm. It's harder to get 2 chips to run at higher speeds than it is for one, this is the same reason why Dell charges more for 1 stick @ 256mb memory than 2 sticks at 256mb. You get higher performance. Try removing one dimm and setting 133fsb, 5/7 timing, cas2-2-2 and see if you can boot. If you can there is your problem, multiple dimms! Sell the other stick if this timing is important to you as the difference between 128/256 is negligible unless you're running win2k.

divinemartyr