Hello all.

I have been experiencing a major problem with my CrossfireX setup. Essentially I am getting poor 3DMark06 results.

My setup consists of the following:

Q6600 (I think running at stock - see my comments below)
Gigabyte GA-EX38-DS4
2 x 2 gigs of 800mhz Corsair memory
2 x 250gigs SATA drives running in RAID0 of the ICHR9 onboard chip
2 x Sapphire 3870x2 with crossifre cable
1000W Thermaltake Toughpower PSU
Antec P182 case

Now I have spent probably over 26 man hours trying to sort out the problem. I have posted on other forums but am coming here to see if any assistance can be given (this is not to downplay the other forums I have posted on, but they are less the technical and do not have as experienced posters).

I have tried the following:
Placing both cards in, install OS, install SP1, install Cat 8.3 then other drivers (with necessary restarts).
Check CCC to see Cat AI on, Crossfire X enabled etc.

3DMarks06 read initially 9600!!!

After a day or two or trying different installation proccedures, installing one card at a time etc, I decided to O/C the CPU.

Interesting the Mobo read the CPU as running at 1.6ghz (instead of 2.4ghz), I up this to 2.4. I then installed EasyTune5 and saw that the CPU was runnign idle at 1.6ghz still. I set Vista power setting to maximum performance.

3DMarks06 now went up to 13330. An improvement for sure, but no where near the 18000+ plus marks others are achieving (on that point I am not sure if other results are mainly O/C'ed).

So, I am at my wit's end as what to do.

Is it (a) a bios/driver issue (b) hardware (c) some incorrect setting (d) faulty card / crossfire cable?

CCC recognises the 4 GPU's, so it appears not to be a hardware issue.

Some people suggested flashing the bios - the 3870x2's may have a clock issue i.e. incorrect read the 2D settings in the 3D settings.

Your comments are greatly appreciated.

When you say crossfire cable you mean the little bridge connecting the 2 cards and not the cable that's outside the case, right?

In case you were wondering why I ask, is because crossfire used to use an external cable between the 2 cards and the monitor, similar to a 3 way DVI type of connection. If you're using that then I'm guessing that is issue.

The external Crossfire cable hasn't been used since the X1900 series cards, since then all Crossfire connections have been internal. But the internal connector bridges have been known to get hot, brittle and this can cause the traces in the connector to break.

3DMark06 results are definitely influenced by the CPU, so if your expecting 18k with quadfire then an OC is required. On my system:

16875 @ 3 GHz
18760 @ 3.3 GHz
20097 @ 3.66 GHz
? @ 4GHz tba

13000 should be spot on with stock 2.4 cpu and stock cards. To reach 18000+ you need to overclock cpu and your graphic cards.

Idleing at 1.6 is because of speedstep and you can turn it off in bios.

Thank you very much for your replies.

Is it worthwhile turning off speedstep? If so, what is the correct bios setting to look out for? I have a quick look but there is no bios settign that refers to speedstep per se (it most likely uses some fancy name!)

C1E or CE1 one or the other. I would leave it on but thats me. If you turn it off your CPU will ruin hotter at idle.

I'd leave it on too.

And don't worry so much about 3dMark scores. Very few games actually need more CPU power than a stock Q6600.

If you're troubleshooting scores than:

turn off speedstep, C1e
use something like RivaTuner 2.08 to monitor clocks
use CPUZ to monitor CPU freq

1x3870x2 on a 3.6 ghz CPU can score close to 17k
3dmark06 scores are pretty much bunk, but unless the program has a problem with 4 GPUs, then I think you have an issue somewhere. So for this situation, I would worry about your 3dmark score.


Also, what mobo is this?

Your right about 1 hitting almost 17000 on a CPU OC to 3.6. That would also be a quad core. 2.4 to 3.6 is a big difference. Also for 17000 you would need to OC your graphics aswell. This guys has the right stuff to hit the right marks. He just has to turn up the juice. He is running stock you see, so why say oh it should be better a OC one gets 17000 OMG WTF something is wrong. I imagine OP should hit 20000+ if he OCs his system to 3.4 and max the GPUs.

I missed the mobo in the OP, my bad.

I think I was @14.4K with my 6850@3.0ghz and single card stock.

I also see so many 6600s @3.6 I forget they are only 2.4 stock, another bad.

I'm having the same problem with 2 sapphire 3870x2s that I finally got around to installing the second one.

With the single 3870x2 I was getting 17,700 with a q6600 at 3.6

I scored less than that with both cards running. Also, I can see the 4 cores in the overdrive section of CCC, but one of the cards (the original one I installed) shows zero GPU utilization. So, something is amiss.

Are you using Vista? I read somewhere that XP drivers don't support 4 GPUs. Don't know if that's still true with the latest drivers.

Are you using the Overdrive tab to monitor GPU usage? I know that when I'm just in the desktop my usage is less than 5%, usually around 1-2% according to RivaTuner, but that's only on the core that my main display is connected to. I've not been able to see all cores at the same time; select one and monitor or adjust. I wouldn't think you'd see usage on all cores in the desktop, what would be the point? But I don't know so....

I would use RivaTuner to monitor the cores you think aren't running and run a benchie.

Well I'm using Everest. After some more unistalling/reinstalling drivers I am now getting GPU usage for all four GPU cores under 3dmark06 but the scores are still less than with a single 3870x2.

Q6600@3.6GHZ

Single 3870x2 - 17700
Dual 3870x2 - 16200

Dissapointing results.

Update - may have found the source of the low scores with 4 GPUs running.

It seems quad GPUs only run under Vista's LDA (linked display adaptor) technology. There is a bit of a description here ->http://www.anandtech.com/showdoc.aspx?i=3256&p=1

Also there is a list of Vista's fixes/tweaks for running multiple GPUs at the bottom of the first post here ->http://forums.techpowerup.com/showthread.php?t=51219