Can't overclock SLi cards.

D

Dan_D

Extremely [H]
Joined
Feb 9, 2002
Messages
63,075
Ok, I did a search for this and couldn't find anything on it. I can't overclock when my cards are in SLi mode.

First thing I expect people are going to ask is if it's a voltage thing since my PSU isn't exactly the strongest out there. It's not bad, but its not uber powerfull.
First off the system works stable and well at stock speeds. I'm powering everything just fine. Also current draw on a 6800GT isn't alot less than that of an Ultra. The speeds I am trying to reach. I even tried overclocking the cards by 1MHz core. ONE MHz! It said the test failed to run at the selected speeds.

I know I am limited by the weakest card. Thing is I have tested each card seperatley and they both go to 400/1100 no problems. Actually both will easily do better than that.

My temps are normal for these cards under idel and load. I've used Rthdrbl to check them.
Now, in case it was a power issue I rigged up a second PSU to just power the cards by themselves. This worked, but didn't change anything.

Both cards have identical BIOS's and work fine in SLi mode or by themsevles.
My specs are in the sig, and I know some people are going to knock the A8N-SLi. Since I am not OC'ing my CPU, and my A8N is working fine, I don't think its that.

Now I did read an article on a website, HardOCP may have had it up I can't remember, that mentioned something about how Asus's PEG Link function screws with overclocking video cards. Ok, so I remembered it from somewhere, well if I adjust any PEG settings in the BIOS the system won't boot anymore and I have to clear the CMOS.

So my question is: What could be the problem? It's not cooling, its not the motherboard being defective, its not power supply related, so what's left? Other than the possible PEG Link in the Asus BIOS.
 
use omniedit and edit the bios's clock speeds to make ultra speeds default. if its a software overclocking problem, this should fix it.
 
lithium726 said:
use omniedit and edit the bios's clock speeds to make ultra speeds default. if its a software overclocking problem, this should fix it.
Click to expand...

Theres a damn good idea. I'll try that. As far as using another driver, my choices are limited since I need to have a SLi driver that allows me to create profiles for some of my games. To which there are only three such drivers I believe. 71.84, 75.90 and 76.10. 75.90's gave me problems before the upgrade to SLi and I can't imagine they'll be better now. I may try the 76.10's.
 
All the 7x.xx drivers game me this problem except the 76.10 drivers and the new 71.84 WHQL drivers. The 71.84 WHQL's are definitley different to the original 71.84's too.
 
I have had no problems OC'ing my 2 SLI'd Ultras using various 7x.xx drivers. They don't seem to OC very far when in SLI but they DO OC. I would make sure that your CPU/RAM is not overclocked and set the PEG settings to default (auto). Also, verify that the SLI selector card is installed the right way (Dual Video toward the slot) and that SLI is enabled in the XP/driver settings.

If that doesn't help I would suggest uninstalling all overclocking utilities, reboot, then install the Coolbits2 registry tweak. Reboot and try to OC using the driver's new OC option.

If none of that works then maybe one of your cards is "slightly" buggy... I really can't imagine what else it could be...
 
Well I am only using the coolbits registry tweak to overclock right now. Both of my cards have been overclock tested for 8 hours straight each, (longer for the primary card, ) as it was the first card I got.

Nothing is overclocked at all. (For a change) As far as my SLi connector card and BIOS settings, everything is working perfectly. SLi is working alright. So it's not any of that.
 
Driver version 76.10 fixed the problem. They overclocked to Ultra speeds without issue.

EDIT: Well the 76.10's didn't like Doom 3 at all. Doom 3 would hang on any of the loading screens and I'd be forced to reset the system. So I won't be using those as I am playing Doom 3 at the moment. (Yes I actually like that game)
 
I used the 75.90a XtremeG's and they worked fine for OC. Let me fire up doom3 real quick to see if they work. Yep, it seems to work. Walked around a bit on the opening level...no problems
 
It's a known fact that the 71.81's won't let you OC in SLI mode. It's mentioned in the release notes.
 
what about 71.84?? i cant get the coolbits o/c to budge at all in sli - every setting fails and only works at default speeds -

bfg 6800gt 370/1.0 stock speeds...
 
TheGamerZ said:
It's a known fact that the 71.81's won't let you OC in SLI mode. It's mentioned in the release notes.
Click to expand...

The 71.81's are one of the only drivers that DID allow me to OC in SLI mode. Go figure.
 
just updated to 76.10 and i can overclock now

435/1100 so far

10,607 3dmark 05'
21,007 3dmark 03'

gpu tests only for those scores
 
You must log in or register to reply here.
Back
Top