2 HD3850s on Maximus Formula - no gain in performance with crossfire - what gives?

[Blue frog]

Looking through the threads here it seems a lot of you have crossfire working well, using HD3850 cards. I am having massive problems with this and hope one of you might suggest some things I can try.

I have recently installed 2 HD 3850s on my Asus Formula mobo. However I'm not getting any improvement in performance under crossfire over just running one HD3850. I am using CCC 7.11, no problems with the image, plays games OK, (except will not run FEAR with CF enabled but will without) runs 3DMark06, no device conflicts shown, both cards are displayed in device manager. No problems with CCC I can see. GPUZ shows CF active. But the scores I am getting in 3DMark06 (about 9K) and 3dMArk05 are the same for the two cards installed, two cards running under CF or even the same if I disable or remove one of the cards. Thus no improvement with crossfire!

I removed the old drivers and CCC for my previous card before installing these new ones and have tried both CCC 7.10 and 7.11but no change.

My PSU is rated for 2 graphics cards. All drivers are the most recent except my BIOS I started with original out of the box and then flashed It to 0602 ( I didn’t want to go to 0802 or 0903 as I read that people are getting high CPU temps with the latter two versions)- I am waiting on a reply from Asus to see if it could be a BIOS problem but this doesn't seem likely as the board is rated for CF out of the box and other people seem to be running CF on it.

CPU is running at stock speed now – was OCed to 3.4GHz.

Has anyone had the same problem or can anyone suggest anything else I can try?

My system specs are:-
Asus formula special edition rev 1
E6750
2 x 1Gb Geil DDR2-800
OCZ Games X Stream 600W PSU rated for SLI/Crossfire
2 x HD3850 256Mb
2 WD 320Gb Caviars in RAID 0

I have tried- (with no success)

Each card on their own
Reinstalling card drivers
Reinstalling CCC
Different versions of CCC (my cards will only accept the 7.11 drivers)
One and two bridges in every combination
Increase PCIE bus speed (suggested by ATI) – no effect
Removed Riva tuner (others reported conflicts with CF)
CCC AI overdrive set to standard or disabled

I am assured by others who have CF running on this mobo that I don’t need to alter any of the BIOS settings

Can anyone suggest anything else that I can try that might help??

My last hope seems to be waiting for the 7.12 CCC and drivers

[xMrBunglex]

i occasionally contribute on ATI's forums to help the nubs and i can confirm that ATI's customer service is absolutely clueless when it comes to troubleshooting CrossFire problems. your problem has me stumped though. do you have Fraps? certain versions of it are apparently recognized as a 3D application, so that can effectively disable CrossFire for you. if you have it set to start whenever Windows starts, you'll have to disable that option as well.

aside from that, i don't know what to say. i also have a 600 watt power supply and all sorts of other stuff running on my system, so don't let anyone tell you you need to buy a 750 watt PSU to run CrossFire. the only other thing i can suggest is to try running a single card in your bottom PCI-E lane to make sure that lane is working. hopefully some others can jump in this thread and we can find out what your problem is.

[newls1]

Been through this exact HELL today aswell, except im using the 3870's. I could not for the life of me get C/F to work on my P5K-DLX motherboard, so I swapped in my new Maximus Formula board, did a *FRESH FORMAT* installed 7.11 driver with *BOTH CARDS CONNECTED TOGETHER* using 2 bridge cards, and all so far has been OK. 3dm06 score went from 13328 to 20500. I can say from this experience, SLi is way easier to get working, and it just seems C/F still has a lot to learn from Sli..... Try switching your cards around, and see if that does anything. Snap me a pic of what GPUz shows for your cards. It should say crossfire ENABLED 2 GPU's, **NOT** crossfire enabled 1 GPU's...

[jimmyz]

Been through this exact HELL today aswell, except im using the 3870's. I could not for the life of me get C/F to work on my P5K-DLX motherboard, so I swapped in my new Maximus Formula board, did a *FRESH FORMAT* installed 7.11 driver with *BOTH CARDS CONNECTED TOGETHER* using 2 bridge cards, and all so far has been OK. 3dm06 score went from 13328 to 20500. I can say from this experience, SLi is way easier to get working, and it just seems C/F still has a lot to learn from Sli..... Try switching your cards around, and see if that does anything. Snap me a pic of what GPUz shows for your cards. It should say crossfire ENABLED 2 GPU's, **NOT** crossfire enabled 1 GPU's...

don't sweat it it reads just like you said on mine too. and It definitely is working here. no problems for install or anything with mine i have run three generations of crossfire though so i guess that may help.


step by step:
1. if old drivers are present i remove then reboot then use drivercleaner.
2. download new drivers.
3. install the cards and hook-up bridges and cable. (on the master card). boot and install drivers. follow directions and reboot.
4. before enabling crossfire i set catalyst AI to standard (as it needs to be on).
5. change any 3-d settings if desired, then go to crossfire box and put a check in it. if it doesn't give you an error message and allowed you to enable then close ccc and try an application.

keep in mind some motherboards like my DFI LP UT P-35 needs the bios set to reflect the second slot running x4 as opposed to 4+1 or whatever yours may say.
gpu-z reads differently on different boards too. so don't pay too much attention as long as it is working in apps.

[hashi]

don't sweat it it reads just like you said on mine too. and It definitely is working here. no problems for install or anything with mine i have run three generations of crossfire though so i guess that may help.


step by step:
1. if old drivers are present i remove then reboot then use drivercleaner.
2. download new drivers.
3. install the cards and hook-up bridges and cable. (on the master card). boot and install drivers. follow directions and reboot.
4. before enabling crossfire i set catalyst AI to standard (as it needs to be on).
5. change any 3-d settings if desired, then go to crossfire box and put a check in it. if it doesn't give you an error message and allowed you to enable then close ccc and try an application.

keep in mind some motherboards like my DFI LP UT P-35 needs the bios set to reflect the second slot running x4 as opposed to 4+1 or whatever yours may say.
gpu-z reads differently on different boards too. so don't pay too much attention as long as it is working in apps.

This would be correct as on my board it reads 1 GPU enabled but ati overdrive +riva tuner show both and they perform accordingly

[Blue frog]

Hi guys thanks for your suggestions. I was beginning to lose the will to live with getting CF working but eventually stumbled on the answer (for me anyway) - quicktime - as part of itunes. Removed it and hey presty Mark6 went up to 11K and then with OC reenabled up to 16K. Runs really well now.

Having two cards running is creating heat issues for me as well as the maximus formula running high NB temps especially when OCed. Thus have added water to the NB (left the CPU with the scythe ninja - if it ain't broke etc).
Cheers
BF