O/C'ing advice for Crucial value pc3200 RAM.

[dagwoood]

I've just upgraded to an Opteron 144 on a Asrock Dual SATA board and it's looking like it will run stable on the highest HTT setting that my board supports(274).

So it's running at 2.466GHz, but I'm currently running my RAM on a divider(133); meaning my memory is running at 176MHz.

Now I would obviously like to run my RAM at, or just over, 200MHz, but if I change the divider to 166 it would be running at 224MHz.

I know that Crucial value RAM isn't ideal for overclocking, but does anyone have any advice if it's possible to get to 224MHz? I can raise the VDIMM voltage to 2.7v, but would this really hurt/damage my RAM?

I was advised to try looser timings, and I have tried 3-4-4-8 at stock voltage but it crashed. So any advice on a good starting point with regards to what timings to use would be appreciated.

Changing my RAM for a better overclockable brand isn't an option at the moment( )some I'm stuck with the "old faithful" variety.

Cheers, dagwoood.

 

[dagwoood]

Get rid of your divider and drop your multi and overclock that way. I have found it a much better way of doing it. I have even had my cpu up to 2.645ghz easily at 11.5x230mhz with more still to go. Have a play with your timings also. You may be surprised at the difference it makes, i know i was.

Thanks for the comprehensive reply pastymuncher

Dropping the divider isn't an option I'm afraid as my motherboard only does whole numbers, i.e.. x9, x8 etc.. So if I dropped the multiplier to 8 and have a HTT of 274, I'd be running at just under 2.2GHz, which is too much of a performance hit really.

When you said "At 232mhz it will run 3-3-3-5", I assume that's at 2.8v? I'd be happy with even looser timings if it'd run stable on 2.7v to be honest.

Thanks again, dagwoood.

 

[dagwoood]

pastymuncher, thanks again for the reply.

I do have the latest BIOS for my board(and I have tried a couple of unofficial beta's as well)and it does only go down in whole numbers.

As to RAM cooling, my CPU fan isn't a large one, but it does shift a lot of air and it vents out onto my dimm sockets(it's on of these Akasa. ).
.
I'll have a play and see what I can run at with regards to timings

Cheers, dagwoood.

 

[dagwoood]

Pastymuncher(and anyone else who's interested ), I've been adjusting the timings and here's where I'm at at the moment.

I can run them at 225MHz on stock voltages with timings of 3-3-3-7. I memtested for a couple of hours and ran Prime for 8 hours without any problems.

No matter what I do, they wont run at 225MHz with a CAS value of 2.5. I've tried really loosening the timings and upped the VDIMM to 2.7v(the max my board supports), but either my system wont boot or memtest fails as soon as it loads

I've run some tests after lowering the Tras value to 6(memtest 2 hours and Prime for 3)and didn't have any problems. I lowered this value to 5 and ran Memtest for 3 hours without any errors, but have yet to run Prime with it set to this value.

All in all, I'm pleased that it's looking like I can run stable at 225MHz, especially at stock voltages and when you factor in that Crucial value memory isn't ideal for o/c'ing.

I think my next purchase though has got to be some lower latency RAM to get the best out of my set up.

 

[dagwoood]

I am lucky in the fact that my motherboard allows the voltage to be upped to 3.2v.
Mine will not run 2.5 on anything but 200mhz and after playing around between 200mhz and 245mhz i found that performance is best at 230mhz @ 3-3-3-5 1T @ 2.8v.

I ordered some Corsair XMS4000PT on Thursday from OCUK to replace it. Has'nt arrived yet though or even had an email to say it has been dispatched.

Pastymuncher, I plan on running Prime over night at 3-3-3-5 but as I'm running with such a high HTT(274)2T isn't an option as my system just crashes I'm not convinced that running with a Tras value of either 5,6 or 7 is going to make that much difference, if any; so I may just go with the 200MHz default values of 3-3-3-8 and know I'm going to have rock solid stability.

I hope your memory is in the post tomorrow

 

[dagwoood]

If you are going to run at the default of 200mhz then do have a go at 2.5-2-2-5 at default volts and you will be surprised of the boost you get.

On second thoughts if you run at default that means you will be running at 1.8ghz. The only thing i can suggest is do the same as me, save up for some pc4000 or faster. Sorry i can't help any further. How did prime go?

Hi pastymuncher. Thanks for posting your Aquamark scores, I knew the CAS value has a major impact on memory speed, but I didn't realise that the Tras value had such an impact on memory performance as well.

I'm sorry I've been ambiguous when I posted running my memory at 200MHz values. I didn't mean run it at 200MHz, I meant run it with the latencies it defaults to if it's run at 200MHz; i.e. 3-3-3-8

I did run Prime over night, but I ran it at 3-3-3-8. I wanted to make sure my system's rock solid at lower timings. This was to make sure my system is stable a slower latencies and not waste my time by running Prime with tighter memory timings, only to have it fail.

But, the goal posts have moved for the moment I've loaded a beta BIOS for my motherboard as this will allow me to use a HTT value above 274. I've increased the HTT to 278 which equates to a CPU speed of 2.5GHz. I kept my memory on the same divider, so now it's at 228MHz. I've ran memtest for 3 hours without any errors, so I plan on running Prime overnight(again!)and see if it's stable. I've set the timings to 3-3-3-8 and haven't had to increase the VDIMM, so it's running at 228 on stock voltage

Thanks again for your input/advice, dagwoood.

P.S. Have you received your new RAM?

 

[dagwoood]

Pastymuncher, I wont mention the RAM

Ran Prime for 12 hours without any errors I could go higher with the CPU overclock but I'd have to lower my divider so I think I'm going to run with this(until I can get some overclockable RAM).

Thanks again, dagwoood.

 

[dagwoood]

Just an update on the situation. I noticed some of my settings weren't saving or were changing but I didn't think too much of it. I downloaded and ran 3dmark01 and my system crashed half way through!

So, my Crucial value isn't stable at 228MHz. I've dropped my CPU speed to 2.4GHz. This equates to my RAM running at 218MHz.

I've loosened the timings slightly, and in conjunction with running it a slower speed, I'm hoping that this will run stable.

I've run Memtest overnight without any errors so fingers crossed

 

[dagwoood]

Those timings are awful especially as it's 2T. It must be your motherboard causing your problems. Are you at 2.7v now?

Hello again pastymuncher

No, I'm at stock voltage. Even if I set it to 2.7v, I can't set the CAS to 2.5 over 200MHz. As to running at 2T, it's one of the foibles of my motherboard that when the HTT value is high, unless you have low latency RAM, you can only run stable on 2T. I've tried running memtest at 1T with different memory timings but it invariably finds errors straight away or crashes.

I've set those timings as a starting point really; I hope to up the HTT and tighten the timings when I've run some more tests.

I'm going to start a new thread over on the overclocking forum as I'm not totally convinced that my RAM was the cause for 3dmark01 crash.

Thanks again for the advice, dagwoood.