Strange memory speed limitations

Dadofamunky

Platinum Member
Jan 4, 2005
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So I just performed a successful motherboard swap on the system in my sig, replacing the Asus mobo with another of the exact same type. Swap went absolutely perfectly.

The system in my sig now passes 4 hours of OCCT and I'm running Prime overnight now, with Linpack still to come. However, that's not what I'm here about. I have G. Skill DDR2-1000 DIMMs that annoyingly cannot run at anything beyond DDR2-800, even though the system does offer a DDR2-1000 option in the BIOS. I am running tighter timings at DDR2-800, though.

My NB voltage is 1.37V and the DIMMs are at 2.1V, which is the spec. at DDR2-1000 Setting the memory to looser 5-5-5-15 timings and DDR2-1000 simply doesn't work. The system won't POST the first time and then upon a reset it just comes back and states the OC failed (the mobo is actually pretty nicely hardened in cases such as this).

I know I'm missing something, because I''ve run faster settings in the past (DDR2-960, for example). One question is: is CAS4 an acceptable tradeoff against DDR2-1000 speeds? In my experience, I've noticed better performance in specific cases at CAS5 with DDR2-960 and up. What can be done? Anything? (I must note, I will be posting a similar topic to the G.Skill forums tomorrow, but I thought I'd start here.)
 

Accord99

Platinum Member
Jul 2, 2001
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Are you able to change the tRC? I've found Asus MBs and G.Skill memory usually work better with the tRC set to 55 or so.
 

Dadofamunky

Platinum Member
Jan 4, 2005
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Oh, good point. I don't think my mobo allows for more than about 42. Darn it. REALLY sucks. I might be able to force it, though... I'll run down and shut off my Prime test to check.
 

Dadofamunky

Platinum Member
Jan 4, 2005
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Yes! well, my board only allows up to 42, but the tRC was set to Auto, so I maxed it out and changed the timings and now the system is running my stress tests again at DDR2-960 (a DDR2-1000 option is also available). Thanks!!!
 

Accord99

Platinum Member
Jul 2, 2001
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No problem, I remember having the same problem with a P5B Deluxe so now I just use a high tRC when ever trying to run fast memory on an Asus MB.