CORSAIR 2GB (2 x 1GB) XMS2 PC2-8500 DDR2 and Maximus formula

[Avi8orJH]

Hi Folks,

I'm a noob to overclocking and my first post here is to thank those who have provided their expertise to this site. As a result of my "studies" here, I've been able to accomplish things I never would have touched a few months ago.
I'd like to share some of my results thus far. I've not seen anything on this particular combination here. I found it interesting that these seem to perform on par with the Dominators.
I appreciate any comments as well as advice on how I might improve on my results. For my needs, timings are as important as speed. This is about as fast as it gets with these timings.
Has anyone ever gotten better from this kit, say maybe, CL4?

Thanks again.

[IMG][/IMG]

[Avi8orJH]

Thanks Timbosan,

You're right, both look a little high in PC Probe. The vNB is set at 1.61 in the BIOS. Everything I've read so far indicates this is about the norm at this speed on this board. I think 1.7 is the limit, though I could be wrong. I had tried to bring it down to 1.58 but couldn't post at that voltage. The NB temp is unusaully high at 63 due to a long stretch of really hot weather in the US midwest. At my average normal room temp, the NB temp stays between 55 and 58 @ idle and no more than 67 at my max load.
The vDIMM is set at 1.98 in the BIOS. I really haven't tried to bring it down lower because of the higher FSB speed. Do you have any suggestions?

Thanks for taking the time to comment.

[Avi8orJH]

No problem.

I would try about 2.0 - 2.02v (asus probe) so if your board is overvolting by 0.08v, set 1.92 - 1.94v in bios for vdimm. Also, try 5-5-5-12, it should be able to handle it. Also try to reduce the TRFC to about 30 (currently at 52 according to memset), it will give you a little better performance and your ram should do it.

I'm currently running at DDR1112 MHz, 5-5-5-12 @ 1.99v (real). I think your ram (like mine) has micron D9 IC's, which can do these timings and speeds. If you want CAS4 at those speeds you will have to bump up the vdimm quite a bit, and it wouldn't be a safe 24/7 setting, but 1000 MHz CAS4 would only take around 2.1 - 2.15v (real) by comparison. However I think 2.1v should be a max 24/7 voltage for micron D9's. Have you got a fan over your ram? It helps to have one as they run pretty hot without one, and it can help preserve them to use one.

If you need that much vNB to be stable, then use it, I am not familiar with X38 boards, just looked a little high.

Thanks alot for the tips. I even managed to drop my vCORE a touch.
vDIMM = 1.92
vNB = 1.57 (must have done something wrong the last time I tried this).
vCORE = 1.37

As for the timings; 5-5-5-12 is a no-go. Hangs @ DET DRAM every time.
This was actually one of the first combinations I tried. I've had these up to 1140 @ 5-5-5-15 and it was rock stable. I can't touch that 12 though. For me, the big number is the tRP. That 3 makes a huge difference for me. Texture loads are much crisper and snapier. I guess I'll give up on cas4. 24/7 stable is more important.
The tRFC really stumps me. The settings in the BIOS are: AUTO, 42, 35, 30, and a couple lower. I can't boot in anything other than AUTO. As you've seen, this defaults to 52 in memset.
Yes, I do have few fans blowin' around in there as you can see from Everest. It doesn't show the fan on the PSU though so there is one more. One of them is in the middle of the case and blows across a part of the RAM and the GPU. I figured with this build, cooling may become an issue . Cheap insurance I think.
About Everest, I'm on the edge as to purchasing. Would you recommend it?

Thank you again for all your help.

[IMG][/IMG]

[zanzabar]

here is what i have without tweaking just 5-5-5-15 trfc 25 pl7 and fsb of 455

[Avi8orJH]

Thank you Zanzabar. If I push to 4.0GHz I see 9900 on the read and 9700s on the write and copy. I had the latency down to 50.2ns. I so wanted to break 10000Mbs/sec and 50ns. Strange thing is, a program that I use most frequently absolutely refuses to run for more than a minute or two if I run >3.925 GHz. I really want to keep the tRP at 3 and while I am able to push faster at these timings, I just can't do it and stay below 3.925GHz. I can't seem to think of a combination that doesn't involve going to a 1:1 strap, pushing the FSB, voltages, and heat, while having to reduce the divider to stay under 3.925. If you have an idea, I would be grateful. Math was never my strong suit back in the day. I'm still coming to grips (slooooooowly!) with the math of overclocking .


*EDIT* Now that I look at it, perhaps those were your suggestions .

[zanzabar]

change to an 8.5 multi and use the divider for 333fsb and 800mhz ram, this is my new one pl8 with phase adjusts set and trfc of 30



i wish that i could use half multies and ive found that the phase adjusts and low trfc make everything work better, the phase make it so that parts of the ram work at the next lower PL so its almost as good in my benching as the full PL7 from 8 with adjusts(u may have to flash to rampage to use phases im not sure)

[mad_skills]

I've kept my 8500C5D Dominators and ~1137MHz 5-5-4-5 @ 2.17V for 24/7:


What revision are those XMS2 of yours?