980 SLI Throttling

[sgloux3470]

So I've had an ASUS Strix 980 for awhile with no issue, had it overclocked past 1500 MHz no problem. I bought a second EVGA SC 980 and even ran that by its lonesome no problems.  Overclock on that was slightly better than the strix.

 

 

Now that they are running in SLI, I crash well before 1500 MHz and while I can complete a run of 3dmark with a ~1400 MHz overclock it tends to crash in games or even running the firestrike demo.  And I've noticed that even if I leave it "stock" (basically the clock speeds that SLI decided, which look like the strix default clocks) it throttles hard in msi kombustor even with only one card running.  

 

The thing is, the temps aren't getting that high.  Top card reaches the mid 70s at worst, bottom card doesn't even reach 70 degrees.  

 

Am I overlooking some sort of temperature sensor that is throttling the card early?  Because these should be able to run comfortable in the high 70s-low 90s without any issue.

 

Here's what it looks like when just the EVGA card is running (side note: this one is way fucking louder than the strix ever was.)  it's throttled all the way down to sub-1000 MHz.

 

 

If I just leave firestrike running, it crashes eventually.

 

As you can see, I peaked at 72/66 for each card respectively.

 

 

I have a 750W power supply that was able to run a 270x CF just fine, so I don't think that's an issue.  I've tried a driver reinstall and it hasn't change things.  My next resort is going to be adjusting the temp target without touching power draw, but I want to avoid having to downclock the card.  I also have a custom fan profile, but I get the same issue with the stock fan and the custom profile. 

 

 

Anyone else have any other ideas?

[Lord_Karango17]

So I've had an ASUS Strix 980 for awhile with no issue, had it overclocked past 1500 MHz no problem. I bought a second EVGA SC 980 and even ran that by its lonesome no problems.  Overclock on that was slightly better than the strix.

 

 

Now that they are running in SLI, I crash well before 1500 MHz and while I can complete a run of 3dmark with a ~1400 MHz overclock it tends to crash in games or even running the firestrike demo.  And I've noticed that even if I leave it "stock" (basically the clock speeds that SLI decided, which look like the strix default clocks) it throttles hard in msi kombustor even with only one card running.  

 

The thing is, the temps aren't getting that high.  Top card reaches the mid 70s at worst, bottom card doesn't even reach 70 degrees.  

 

Am I overlooking some sort of temperature sensor that is throttling the card early?  Because these should be able to run comfortable in the high 70s-low 90s without any issue.

 

Here's what it looks like when just the EVGA card is running (side note: this one is way fucking louder than the strix ever was.)  it's throttled all the way down to sub-1000 MHz.

 

 

If I just leave firestrike running, it crashes eventually.

 

As you can see, I peaked at 72/66 for each card respectively.

 

 

I have a 750W power supply that was able to run a 270x CF just fine, so I don't think that's an issue.  I've tried a driver reinstall and it hasn't change things.  My next resort is going to be adjusting the temp target without touching power draw, but I want to avoid having to downclock the card.  I also have a custom fan profile, but I get the same issue with the stock fan and the custom profile. 

 

 

Anyone else have any other ideas?

I had the first part of your problem, with a lower overclock in sli with my 760's however they never throttled like that.

 

It does seem like a power related problem, however with maxwell's power efficiency (your cards probably draw as much power as my 2 760's drew), it would be unusual to encounter such problems with a 750W PSU.

 

Does the app only crash, or does windows give a message along the lines of "driver crashed and has recovered successfully"?

[deusvult]

Whilst I personally didn't encounter this i've seem some talk on the EVGA forums about this specific problem. You can find a BIOS flash there that supposedly fixes this problem, I'd recommend just taking a peek and see for yourself if that's what you're after. 

[sgloux3470]

I had the first part of your problem, with a lower overclock in sli with my 760's however they never throttled like that.

 

It does seem like a power related problem, however with maxwell's power efficiency (your cards probably draw as much power as my 2 760's drew), it would be unusual to encounter such problems with a 750W PSU.

 

Does the app only crash, or does windows give a message along the lines of "driver crashed and has recovered successfully"?

 

I've had the app just crash if it's a game or something but usually I get a full display driver crash.  What happens is I put firestrike on loop while I go do something else and come back to my windows login screen, so I get the sense that the whole thing is crashing.

 

 

Whilst I personally didn't encounter this i've seem some talk on the EVGA forums about this specific problem. You can find a BIOS flash there that supposedly fixes this problem, I'd recommend just taking a peek and see for yourself if that's what you're after. 

I'll look into it.  Thanks for the tip.

[sgloux3470]

Okay so raising the power limit does prevent msi kombustor from throttling, but I'm still getting crashes. GTA V is basically unplayable since it crashes to desktop even when downclocked to stock 980.  It may just be a GTA V issue though, but it wasn't crashing on a single 980 before.

 

The cards aren't even be taxed 100% in GTA either since I have g sync capping it at 60 FPS.

[CalculuS]

Okay so raising the power limit does prevent msi kombustor from throttling, but I'm still getting crashes. GTA V is basically unplayable since it crashes to desktop even when downclocked to stock 980.  It may just be a GTA V issue though, but it wasn't crashing on a single 980 before.

 

The cards aren't even be taxed 100% in GTA either since I have g sync capping it at 60 FPS.

Do they crash in other apps? Can you complete firestrike/heaven?

[sgloux3470]

Do they crash in other apps? Can you complete firestrike/heaven?

 

Yeah firestrike works fine.

 

I ran both valley and heaven in SLI and with a single card on Extreme settings.

 

Valley

SLI-3553

Single-2727

 

Heaven

SLI-2813

Single-1642

 

Seems like it might be a power supply issue afterall, or a driver one. (Will try reinstalling again)  

[CalculuS]

Yeah firestrike works fine.

 

I ran both valley and heaven in SLI and with a single card on Extreme settings.

 

Valley

SLI-3553

Single-2727

 

Heaven

SLI-2813

Single-1642

 

Seems like it might be a power supply issue afterall, or a driver one. (Will try reinstalling again)  

 

I think you are pushing them both too hard causing the psu to make subtle crashes and whatnot.

[sgloux3470]

Reinstalled drivers and it seemed to help some, valley went to 3748 and Heaven went to 2895.  Might just be random variance though.

 

 

Still can't overclock worth a shit though.

[Guest Philosophy]

Well they are packed in there tight what are the temps?

[sgloux3470]

Well they are packed in there tight what are the temps?

 

Top card usually in the mid-high 70s, bottom card in the high 60s.  Kombustor will nibble on the 80s.

 

Should be good up to 90+ degrees though.  

 

They both idle very low, at around 59/45 degrees for top and bottom respectively.  

 

Both cards were running perfectly fine on their own in the 70s degree range without throttling.

 

I'm going to test out a few more games tonight and see if I run into more issues. I'll try running  BF4 for awhile.  

[Guest Philosophy]

Top card usually in the mid-high 70s, bottom card in the high 60s.  Kombustor will nibble on the 80s.

 

Should be good up to 90+ degrees though.  

 

They both idle very low, at around 59/45 degrees for top and bottom respectively.  

 

Both cards were running perfectly fine on their own in the 70s degree range without throttling.

 

I'm going to test out a few more games tonight and see if I run into more issues. I'll try running  BF4 for awhile.  

Yeah those temps should fine for sure. My guess is then power supply. 

[sgloux3470]

It's possible, but 750W should be more than enough from the benchmarks I've looked through.

[sgloux3470]

So other games seem to be working fine now.  GTA V install is being validated as apparently it wasn't patched properly or some shit.

 

Seems to be resolved for now since raising the power limit stopped the throttling and it doesn't crash the display driver anymore. (Shame I can't overclock it though. Would really like the extra 20 FPS.)

[sgloux3470]

Just wanted to post this here in case anyone comes searching for an answer in the future.

 

So I discovered today that my voltages on the two GPU's were mismatched, with the EVGA SC running around 1.0 V and the Strix at 1.2 V which was creating the overclocking instability I was experiencing.  

 

As per this thread: http://forums.evga.com/GTX-980970-SLI-voltage-mismatching-issue-m2244800.aspxI increased the clock on the strix more than the evga sc and it appears to be holding much better, more stable overclocks.  I haven't pushed it all the way but I'm confident I can reach 1500 MHz now.  BIOS fix would have likely resolved this too by flashing the EVGA SC card.  Definitely going to avoid recommending the EVGA SC to anyone since it seems to be a prevalent issue.