Which Display Drivers? m9750 Crossfire 3870s

I'm currently using AMD Legacy 12.6, however CCC won't show option to enable/disable crossfire. Device Manager/GPU-Z/CCC properly detects both adapters. OpenCL unchecked in GPU-Z.

I re-installed the drivers using DriverSweeper, but still no luck.

Am I using the wrong drivers? Any help appreciated. Thanks.

 

So it looks as though 12.6 are the only drivers that will install on my computer. I still haven't been able to run both cards together on a bench. Right now 3dMark06 yields 8700. Master will take 100% load while my slave will take 0%. I disconnected my CrossfireX cable and of course, there is absolutely no difference in hardware specs. My computer still detects both cards yet I still can't use the second card.

I did notice that all my software reads each card as a "X2." I'm not sure if this is normal. It would appear in HWMonitor that I effectively have two 3870 X2s. Temps on my slave card run parallel to my CPU, which seems normal given it isn't ever under load. The only thing I can think of at this point is a hardware failure between 1 of my 2 graphics cards or the crossfireX cable itself.

I'm at a loss for ideas. I'd really like to get this working without having to replace hardware now.

 

Are you sure the crossfire cable is good? Is the master running a master VBIOS, and the slave running a slave VBIOS? A user here back in 2008 named ichime (I have a good memory ) was able to get his to work in crossfire. He used catalyst ver 8.7. It's old but perhaps if you can find the old version on the web you can at least see if it works for you. Here is his thread with TONS of info.

http://forum.notebookreview.com/ali...319975-m9750-ati-mobility-3870-does-work.html

Save the webpage while you still can, not sure how far back this forum goes but I imagine eventually it will be deleted.

Don't forget to let us know how it goes!

 

Thanks for your suggestions, Pro. I did try V.8.7 just to be 100% sure I had the correct drivers but they wouldn't install. Reverted back to 12.6. After some thought I did a quick search for defective crossfire cable troubleshooting and I soon realized that CrossfireX doesn't work unless in full screen. I had no idea of this.

Low and behold I try GW2 in full screen and Afterburner displays both my GPUs under load! All week I've been at this wondering what the hell. Apparently I had it working correctly and a 3DMARK06 score of 8700 utilizes both GPUs. I noticed others with the same hardware hitting close to 10k which is why I assumed only one GPU under load. Why I only ever seem to hit 8700 I'm not sure, perhaps due to Windows 8.

I never did find an on/off option for CrossfireX in CCC settings.

 

Your lower score is probably due to your CPU bottlenecking the card. Most laptops that came with a 3870 installed from the factory probably had better CPU's in them and thus a higher score. My M5750 is the same way, I slapped in a 4850 though my T7400 is holding it back so it's scores are lower than a laptop the came with the 4850 out of the box.

Just in case though, use a tool like HWMonitor to monitor the temperature of the GPU. Make sure it's not running too hot and throttling itself.

Also if you have a tool like the "Kill-A-Watt" that newegg sells that will monitor watt consumption of a device, you can plug your laptop into that and make sure it is not close to pulling the max watts of your PSU under load. If it is your laptop may be power starved. After my 4850 I did this and realized my laptop was pulling a constant 120W which was the max of my OEM power adapter. I had to purchase a 240W power supply for my laptop (which was a project on it's own finding one that had the right tip and power ratings) and that solved my issue, also fixed stuttering in games.

 

I pulled a t7600 from an old Dell which is the fastest available CPU for this thing. I have it running stock though, at 2.33Ghz. As far as temps - I had trouble with my first card as it would run near 100C under load. It rarely peaks higher than 85C now with a copper shim and some ICD7. I also have the CPU undervolted which helps the temps of my slave card as they're both on the same heatsink. I wouldn't say the CPU is bottlenecking me here, unless others have benched this setup on OC.

Interesting to hear that you resolved some power issues with another adapter. I never would have thought to change mine, it's the OEM 180W currently.

 

Yeah you M9750 owners got a nicer PSU than us M5750 owners did, ours was only a 120W. What temps are you seeing with the CPU and slave card?

On my M5750 the CPU & GPU also share a heatsink but I did not have to undervolt anything to keep the temps cool. Under load I never go over 80C.

I used 3DMark Vantage to test my laptop and I say the CPU is bottlenecking because my T7400 (next model down from yours) CPU score was a lot lower than the GPU score. Since 3D mark uses both if one is weaker it will drag the other score down as well.

Have you thought about getting a T7600G into your laptop? That's the best cpu for this socket. My M5750 supports it so I imagine your M5950 would too.

 

You're right, T7600G is the fastest CPU for these. I didn't realize the difference between what I have (T7600) and the G until after installation when I couldn't OC from bios. Undervolt was easy though and significantly lowered my temp (By nearly 10C if I recall). Now under load it shouldn't hit more than 80C with MX-3 paste, 22C ambient temp. Without Crossfire it would run as cool as 63C under load.