Personal computing discussed

Moderators: Flying Fox, Thresher

 
Fragnificent
Gerbil Elite
Topic Author
Posts: 955
Joined: Tue Feb 05, 2008 4:28 pm

Correct timings for XMS6400/x38

Mon May 05, 2008 4:14 pm

Hi everyone. OK, I know quite a bit about PC hardware, including programming tiny mundane crap as arcane as registers in the Northbridge and peripheral chips and at one point I could name all the pin signals on the old Pentium Pro. So yes I am a dork. But, One thing I never really got is RAM timings. I understand theres a front porch and back porch, and what all the terms mean, RAS-to-CAS delay, etc etc. What I cannot find for the life of me is what these are supposed to be set to in my current machine. I have a Shuttle SX38P2 with an X38, and 4x1 GB of Corsair XMS PC6400. I believe it is supposed to be set to "4-4-4-12" but what does each number refer to? The four numbers I know about are tRcd, tRp, tRAS, and tCAS. I'm assuming that 4-4-4-12 means CAS4, tRcd=4, tRp=4, and tRAS is 12. Is this correct? Also, ram is listed as 2.1v but the x38 defaults it to 1.8v. Should I manually set this? Yes I know there are like 100 threads about this already but none of them confirm this information for me to any degree. Help!?!?!
*** Shuttle X48 / 4 GB Corsair PC6400 / C2D E8400 @ 3.6 Ghz / Radeon 5850 / Caviar 750GB / Windows 7 Pro 64-bit ***
 
Flying Fox
Gerbil God
Posts: 25100
Joined: Mon May 24, 2004 2:19 am
Contact:

Re: Correct timings for XMS6400/x38

Mon May 05, 2008 9:09 pm

Fragnificent wrote:
I have a Shuttle SX38P2 with an X38, and 4x1 GB of Corsair XMS PC6400. I believe it is supposed to be set to "4-4-4-12" but what does each number refer to? The four numbers I know about are tRcd, tRp, tRAS, and tCAS. I'm assuming that 4-4-4-12 means CAS4, tRcd=4, tRp=4, and tRAS is 12. Is this correct? Also, ram is listed as 2.1v but the x38 defaults it to 1.8v. Should I manually set this? Yes I know there are like 100 threads about this already but none of them confirm this information for me to any degree. Help!?!?!
There is a TR article that talks about the 4 numbers and latency (under misc category I think). I think you have the numbers correct IIRC. As for the voltage issue, this usually means the BIOS will default to 1.8V and will at least boot into the BIOS for you to change it. It should probably not run stable at 1.8V. I would say change that to 2.1V first and then memtest it. If you feel adventurous you can try lowering it 0.1V at a time and retest.
The Model M is not for the faint of heart. You either like them or hate them.

Gerbils unite! Fold for UnitedGerbilNation, team 2630.
 
Fragnificent
Gerbil Elite
Topic Author
Posts: 955
Joined: Tue Feb 05, 2008 4:28 pm

Re: Correct timings for XMS6400/x38

Tue May 06, 2008 9:22 am

Yeah I tried setting to 2.1v and this resolved a few issues. Apparently Corsair is speshul.
*** Shuttle X48 / 4 GB Corsair PC6400 / C2D E8400 @ 3.6 Ghz / Radeon 5850 / Caviar 750GB / Windows 7 Pro 64-bit ***

Who is online

Users browsing this forum: No registered users and 1 guest