Overclocking Crossfire X1900

[Durzel]

Wondering if anyone can help me...

I've got X1900 Crossfire (X1900XT and X1900, both HIS with the IceQ3 coolers).

I've been using ATI Tray Tools recently and overclocking (I guess?) one of my cards to 685/810 with vGPU 1.425v. No other voltage option changes.

I thought this was working well for me, except when I ran 3DMark06 I actually ended up with a lower score (about 9400) with my E6700 at 4.3Ghz than I did when I overclocked my cards individually with ATiTool to 680/800, with my CPU running 3.6Ghz (got 11335 then!).

As I've disabled both ATI services am I right in thinking then that one of my cards is running at 685/810, and the other is running at the 2D speeds of 500/600?? I can't think of what else could cause my scores to be so much lower.

So last night I tried ATITool again, set up a profile for 685/810 (1.425v/2.086v/2.086v, and whatever the other one is by default) but the problem I'm having is that I can apply this clock to one card, but when I choose the other card in the drop-down menu and apply the same clock my system will always stop responding shortly afterwards... screen goes black, monitor switches off, etc. It doesn't seem to matter which card I apply this 685/810 speed to first, as soon as I apply it to both I just get a lockup.

Is the problem as simple as not running enough voltage for the overclock? Is there something else obvious I'm missing?

Also - how do I know which card I'm overclocking when I choose one from the drop-down menu in ATITool? Does CCC overclock both cards at the same time when you set clocks in Overdrive?

Also - finally - when I boot Windows the screen goes black and comes back about 3 times, is this normal when Crossfire is enabled?

 

[FreeStream]

Firstly, CCC and ATI Tray Tools only overclock one card.

2ndly, you need to have two profiles for each card.

Start from Voltages --> Fan Speeds and then set the clocks. Try stock clocks first. 650/775 @ 1.4/2.089/2.089/1.487V

Save the profiles as card 1, and card 2. Make sure both cards have the correct options.

Then load them one by one.

I think that should work.

 

[Durzel]

One thing I've just noticed which is really stupid (of me possibly) is that I followed an overclocking guide and created profiles in ATITool for "X1900XT" and "X1900XTX" with their corresponding standard clock speeds. I set the voltage to 1.425v, saved it for "X1900XT" and each time I raised the clock and saved the new profile (i.e. "X1900XT", then "X1900XTX", then "Daz 3D OC" which was 685/810).

What I've just found out is that it only saved the voltage settings for "X1900XT", the other overclocks ("X1900XTX" and "Daz 3D OC") kept the original 2D voltage of 1.175v....

So basically I was trying to run both cards at 685/810, at 1.175v.

I saved 1.425v vGPU for all of the profiles individually and am now benching at 685/810. Doh!

 

[Durzel]

Well, 3DMark06 finished.. and I got 11432 3DMarks (E6700 @ 4.3Ghz, 685/810)

By comparison I got 11335 at 3.6Ghz (680/800).

Am I guessing therefore that I'm pretty much GPU limited?

 

[Jakus]

Well, 3DMark06 finished.. and I got 11432 3DMarks (E6700 @ 4.3Ghz, 685/810)

By comparison I got 11335 at 3.6Ghz (680/800).

Am I guessing therefore that I'm pretty much GPU limited?

Funny, I've been playing with a 1950 crossfire setup and came to the conclusion the cpu was holding them back !
6600 conroe @ 3.2 ghz 11,252 in 2006 cards not overclocked

You might like to have a play with Aquamark 3 ( look for the patch also) it's a quick and consistant test and gives you a bit of an insight to CPU/Gpu relationship

 

[Durzel]

Well, in 3DMark06 I'm getting an extra 500 or so in the CPU benchmark but - ironically - losing about 200 or so on the actual tests. I guess this is because I'm running it on a proper day-to-day Windows install now as opposed to a completely vanilla one (as I did for initial benching).

Managed to get 11672 by cranking my cards up to 681/864. Still a bit disappointed, I expected the extra 700Mhz to give me a healthy boost to 13k+

As an aside I found out last night that one of my cards will do about 873Mhz before showing artifacts, whereas the other will do about 925 - I guess this means both cards have BJ11 (1.1ns) memory?

Compare URL is: http://service.futuremark.com/compare?3dm06=579853 ..if anyones interested.

Thanks for all the help so far.