Corsair xms2 DHX timings problem!!!!

thegeneral

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Mar 13, 2009
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I've been having problems where setting the memory timings in the BIOS to 4-4-4-12 2.08V causes the start up to hang for another 30-40 seconds and then CPU-Z shows the timings to be 5-5-5-18 instead!

My system is:
N7AD-SLI motherboard
Intel q9550 2.8mhz cpu
Nvida nforce 250 1024mb DDR3 graphics card
2 x 2GB Corsair XMS2 DDR2 DHX memory
150GB WD Velociraptor HDD

BIOS Settings for chipset are:
tCL - 4
tRCD - 4
tRP - 4
tRAS - 12
tRRD - Auto
tRC - Auto
tWR - Auto
CMD - 2T
Dram voltage - 2.08 (nearest to 2.1 is either 2.08 or 2.14. Changing to 2.14 doesn't work either!)

I'm having trouble finding out the recommended settings for this motherboard and why the memory doesn't seems to change even though it's set in the BIOS!

Can you help?! ;)
 

SpidersWeb

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Aug 19, 2009
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I have Corsair XMS2, it's not 4-4-4-12? 5-5-5-18 are the specs advertised (unless there was a CAS4 version I don't know about??).

Best I could get was 5-4-4-12 (freq is 930Mhz I think), that's with the DDR2/1066 XMS2 (rated 5-5-5-18 @ 1066Mhz @ 2.1V).


Edit: also I found raising the voltage doesn't do anything for CAS, makes sense to me, can anyone here confirm if I'm wrong or right about that point?
 

thegeneral

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Mar 13, 2009
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Hi SpidersWeb,

The memory I have is the CL4 version although there is a CL5 version which I think you might have. The timings for the CL4 are supposed to be 4-4-4-12 2T at 2.1v.

I've run memtest86+ for 4 passes and it reported no problems. I've run Prime95 on the memory stress test settings for over 8 hours straight. Nothing! That proves at least the memory hasn't got a fault I think?

The problem now relates to how do I set the timings which are stable and why does CPU-Z and Everest keep reporting the memory settings different even though they are set in the BIOS?!

I've asked these problems on the Corsair forum and no one has responded, which isn't good. I've also sent an email to ASROCK and nothing either. Someone must have a good idea of what to do and I hope to find them on here..... ;)
 

SpidersWeb

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What frequency is the RAM running at?

Only thing I could think of was that it's failing at CAS4, so the BIOS reverts to safer settings. Just a thought, I don't know as I'm not familiar with your setup (not enough experience, hoping other people post up here).

I'm using a P45 chipset. I did find on the P45 (different to yours I know) that when using multipliers e.g. running RAM at 533Mhz with a 333Mhz FSB worked fine until I started raising the FSB. (while the DRAM req was still well below the rated limits).

I am using an Asrock board as well btw. Just different chipset.