I recently bought a 7950 crossfire arrangement, it works until i play FarCry3 and some instances of Youtube.

1. Total freeze - can't access TaskManager. Have to use RESET buttton.
2. Total freeze - can't access TaskManager and my Keyboard/Mouse LED's turn off, but screen and sound remain stuck. Have to use RESET buttton.
3. Partial freeze - W7 remains intact, catches error and allows me to access TaskManager and/or press the now windowed game's CloseWindow button.

Problem was the following: At a seemingly random time, the computer would freeze in one of the three ways stated above. At first it was only 1 and 2. So cleaned my PC of all drivers and software for my GPU setup, Defragged, wiped clean space and ran a registry cleaner. Followed by a reinstall of everything removed. Tested FarCry3 and got multiple instances of type 3, until i used the HBAO setting and got either a 1 or a 2, set HDAO for a mix of crashes. It has returned to being either a 1 or a 2 again. So i have multiple questions that need answering, such as why does this happen in said ways and why do my peripherals die are the first two of many really.

Side notes: Temps seem normal, i log CoreTemp readings and no core surpassed 72C before crash. Crashes in other games which are very rare are always handled to the best of my memory. I have tested my CPU and Memory and they seem to be ok. The errors that were caught are logged as FC_d3d11.dll errors.The catastrophic failures have no logs, which suggests that it's a new interface problem between W7 Kernel and ATI drivers for this game, i think.

RAID 0 SSD x2 (14Gb empty)
Z77XGDA-UD5
I73770K 4.5GHZ
8GB DDR3 2.4GHZ
7950 x2XFIRE via HDMI cable (ASUS 900Mhz/1250Mhz/1094Mv and Saphire 830Mhz/1xxxMhz/08xxMv) ASUS is the primary with the HDMI output used and Saphire is the slave set to mimick ASUS. MSI Afterburner sets both cards to 1000/1450/1094Mv.
750Watt PSU Bronze80+

I will add information as of when i can to this post in this thread. Thanks.

Sounds like one or both of the cards are unstable, try setting the clocks for both cards at 800/1250 @ stock voltage and re-test FC3.

Update of testing: Just had crash type 1 with the stock settings for the ASUS card for both cards. Will now test with default rates for the Sapphire on both.

Update of testing: With the default sapphire settings i chose, i had crash type 1 after a few minutes.

New Sidenote: I wanted to check which card was which just for diligence, in MSI After Burner i switch Master GPU to number 2 and pressed the reset button and was given a default clock of 950Mhz/1250Mhz/(1094Mv presumably because ASUS needs at least that). I think my second card is this rather than this I opened the case and it looks like the OC edition.

I freel soo ronrey ;(

Try running at 800mhz core, 1250mhz vram and 1150 mv (settings that any working 7950 should have no trouble with) or/and test each individually as a preliminary to see whether its a case of unstable oc/voltages or dodgy card.

eddyr said:

Try running at 800mhz core, 1250mhz vram and 1150 mv (settings that any working 7950 should have no trouble with) or/and test each individually as a preliminary to see whether its a case of unstable oc/voltages or dodgy card.

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I tested 800, but ran out of time as i had to be somewhere and testing requires me to play FarCry3. The card looks identical to the OC version, how can i assess whether the BIOS is default, is there some mechanism by which i can compare the card's architecture to expected architectures through some AMD application?

Also, i don't know whether you read the whole of my initial post, but, i can play all sort of other GPU intensive games like BF3, Crysis2, RO2 for hours on end without problems.

Update: the Sapphire is the OC edition according to seller, meaning 950/1250. I measured VDDC for both cards and they are different. This must be a FarCry3 issue no? Please chime in..

Cards are unstable. FC3 wouldn't play with 1250MHz on my 2x680s. I had to run at default. Not sure why. BF2 loves the OC, as does ARMA2

eddyr said:

Try running at 800mhz core, 1250mhz vram and 1150 mv (settings that any working 7950 should have no trouble with) or/and test each individually as a preliminary to see whether its a case of unstable oc/voltages or dodgy card.

Click to expand...

I've tested both cards at 1000Mhz/1450Mhz/1094mV for 2 hours each alone using the stability test that AIDA64 provides. The lower card, Sapphire, get's about 15C-20C hotter than ASUS, but that's because it sits below. No crashes nor anything else remotely worrying.

The part of all this that concerns me the most is the way the whole OS fails to respond when a severe error takes place in FarCry3 and once or twice in YouTube. Should i raise VDDC to 1150mV for both cards and if so, why?

BaDBoY_uK said:

Cards are unstable. FC3 wouldn't play with 1250MHz on my 2x680s. I had to run at default. Not sure why. BF2 loves the OC, as does ARMA2

Click to expand...

What do you mean by 'cards are unstable'?

1150mv is a a safe voltage bump (temps permiting), just to check whether it could be due to instability. Some games are more sensitive than others to unstable overclocks and it could be FC3 was highlighting the instability. My intial suspicion was that the saphire could be struggling at 1000mhz core. Upping the voltage and lowering the clocks were simply to set them both at speeds and voltage most(all imo) fully working 7950's shuold be able to operate at (again temps permiting).

Having said that farcry3 is a little unpolished (at least when I played it), is it up to date and are you using the latest drivers?
When you tested each card individually at 1000mhz/1450/1094mv it ran FC3 without crashing?

Also how hot does the sapphire get? Some 7950's really dont like higher temperatures, Mine doesn't like to go above 1050 core unless I keep core temp below 65C and the vrm's below ~75C.

Is the youtube caused crash flash related? Could be just flash being a PITA or perhaps the 2D clocks/volts are an unstable combination on one of the cards.

eddyr said:

1150mv is a a safe voltage bump (temps permiting), just to check whether it could be due to instability. Some games are more sensitive than others to unstable overclocks and it could be FC3 was highlighting the instability. My intial suspicion was that the saphire could be struggling at 1000mhz core. Upping the voltage and lowering the clocks were simply to set them both at speeds and voltage most(all imo) fully working 7950's shuold be able to operate at (again temps permiting).

Having said that farcry3 is a little unpolished (at least when I played it), is it up to date and are you using the latest drivers?
When you tested each card individually at 1000mhz/1450/1094mv it ran FC3 without crashing?

Also how hot does the sapphire get? Some 7950's really dont like higher temperatures, Mine doesn't like to go above 1050 core unless I keep core temp below 65C and the vrm's below ~75C.

Is the youtube caused crash flash related? Could be just flash being a PITA or perhaps the 2D clocks/volts are an unstable combination on one of the cards.

Click to expand...

The Sapphire is the OC version meaning it's default state is 950Mhz/1250Mhz. The tests i ran were using AIDA64 stability profiling, it's a system burner. Sapphire reaches 75C Diode and 84C VRAM. Youtube hasn't crashed since i reinstalled all the drivers. I bought one card, set it all up, bought another, after reinstalling everything clean onto the crossfire setup that problem has disappeared. It is just FC3.

Since writing that i have had several desktop crashes.

Read what people are saying: put it back to stock. It sounds like you've got an unstable OC.

Rusty0611 said:

Read what people are saying: put it back to stock. It sounds like you've got an unstable OC.

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+1

FC3 is a very demanding game for graphics

Load up a copy of Unigine Heaven 3 and downclock your cards untill they can do about 10 or 12 laps of Heaven 3 without crashing.

^yep.

Take everything to stock, cpu, memory and both cards, if possible remove one card and try each individually and test.

Also what brand psu do you have?

Rusty0611 said:

Read what people are saying: put it back to stock. It sounds like you've got an unstable OC.

Click to expand...

I have read what people have said. I have tested stock on both cards. The game just crashed on sub-stock levels with 1150mV. It isn't an unstable GPU OC which is obvious if you read my initial post.

I'm starting to think i need to down-clock my CPU.

What happens if you disable xfire and run at stock? Do you still get crashes?

I've reduced my CPU rate from 4.5Ghz to 4.0Ghz and had FarCry3 on all day long.

What did you stress test the cpu overclock with? Did you not use prime or even better a short burst of IBT @ maximum?

I dont think your that far off stability though as your errors are not blue screening or forcing a reboot all the time.

3. Partial freeze - W7 remains intact, catches error and allows me to access TaskManager and/or press the now windowed game's CloseWindow button.

Click to expand...

Up the volts a little on the CPU and get stuck in with FC3.I get the exact same thing when i push 4700 and 1866 ram at 8.8.8.24-1T UDK.exe crash after an hour.Nothing major probably needs just a tad more volts to keep it happy.