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7950 problem with 3D clocks

enhanced08

Weaksauce
Joined
Feb 21, 2006
Messages
123
I have two fairly new 7950 video cards, both of which have the same issue. They will each boot windows, display a desktop and run just fine but as soon as they switch to 3D clock speeds the whole system locks up.
I thought it was a cooling issue so I pulled off the heatsink, removed the thermal pads from the vRAM chips/VRMs and removed thermal paste from the GPU. I then reapplied AS5 and added Fujipoly thermal pads to the VRMs and Ram chips.

This did not help any, the system is stable with any other card(s) in it, its just these two cards.

Any idea why they are acting up like this?

They have been like this for awhile and thinking back on it, one worked fine for awhile and suddenly would lockup and the other I reapplied the thermal paste/pads as soon as I bought it.

thanks
 
What's your power supply? What other cards have you tried? How fresh are your AMD drivers?
 
Numerous combinations....

Power supply is currently a 1000watt (forget the brand) but another system I tried the cards in had a Magna Gold Series 1200watt.

Have tried other 7950s, both the same brand/model and different brand/model.

Drivers are v13.1, ive tried reinstalling them as well as reinstalling the OS multiple times

Everything Ive tried points to a problem with the cards but I have no idea what that might be.
 
13.1 are old drivers, but it sounds like you're mining or folding and want that specific driver version. Have you tried those two cards in another system?
 
I am mining actually, however that doesnt matter here. Loading up a game or folding client nets the same result.

Yes, I have tried the cards in a few different systems, some Linux some Windows, different drivers etc....

I can take a rock solid system and swap one of these cards in, it will crash as soon as the program loads and starts pushing the video card. Swap the cards back and it works fine.
 
Thanks for sharing all of that. Yeah, it's likely that those two cards have borked hardware. You can try underclocking them with Afterburner, but an RMA (if they're still under warranty) sounds like it's in order.
 
I don't think I can RMA it since I've removed the heat sink on both.
I wish I could figure this out. :(

Thanks for the help.
 
Haved you tried the bios switch and loaded a different bios?

Also removing heat-sink doesn't void warrenty(generally speaking), as long as their is no sticker on one of the screws.

I have re-timmed several cards and all are still within warrenty.
 
I have not tried the bios switch but will tonight.

I did not see any sticker on the screws, maybe i'll try an RMA. The problem then will become that there are no 7950's in stock right now. Maybe I could get a store credit?
 
No luck with the bios switch. I did not try loading a different bios but I doubt it would make a difference.
 
I havnt given up just yet...

I tried flashing a different BIOS (specifically one with a lower gpu voltage), this didnt solve the problem however it did something. Now rather than the entire system locking up as soon as a load is applied to the video card I am able to watch the temp VERY QUICKLY spike to over 85C and then the program shuts down (a failsafe to prevent burning up cards). I assume the lower voltage keeps the temp just slightly lower, enough for the program to detect the high temp and shut it down rather than locking the whole system.

So it looks like a temp issue. I removed all the thermal pads, cleaned everything every well and am now waiting for it to dry. I am going to try running it with no pads on the ram just to see if maybe I got too think of pads.

Anyone know what thickness I should use? I think I got 1mm for the RAM and .5mm for the VRMs.
 
It depends on the cooler. Some manufacturers recommend 0.5 mm all around, others says 0.5 mm for RAM, 1 mm for VRMs.
 
Put one card in at a time.

With each card use MSI afterburner and see what the default clock and voltage is. You might have a lower voltage card running in the 1st slot while your 2nd GPU isnt getting enough voltage.

Find the card with the highest default voltage and place it in the 1st x16 slot and you should be fine unless you are having an issue with a card itself. In that case, RMA as said before.
 
The cards are reference Sapphire brand.

I had 1mm pads of the VRMs and .5 on the ram, with this the card runs fine with 2D clocks but over heats when it jumps to 3D and a heavy load.
When I remove all RAM pads it will boot and run at 3D clocks with no issue (other than the ram chips getting hot).
If I put .5mm pads on ram and VRMs, the system locks up.

I looked for a smaller pad but .5mm is the smallest I could find. Would some AS5 work on the RAM or is this not advised?
 
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