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Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Thu Oct 15, 2020 7:34 pm
by FlyingPenguin
I was working behind my gaming PC the other day because I seemed to have a bad monitor cable on my secondary monitor. While working on that I noticed (because I had a game running) that the exhaust coming out of the video card was so hot, I was concerned it would (or had) damaged the cable.

So I installed MSI Afterburner to see what my temps were and I was shocked. The card was running at 82 degrees C. That's MAX temp for that card. That card has an 82 degree cap, after which it throttles down the clock to keep the temp below 83 C. So I was essentially losing around 100MHz of clock speed (the GPU clock was throttling down to around 1730 MHz from the actual max boost clock of 1833).

So I scrolled down to the fan speed monitor in Afterburner and get another shock. Even at 82 C, the fan was only running at 54%!

A little more digging and I found that the fan curve was practically flat, It starts at 40% and tops out at 54%.

Now this is the single fan blower stock NVidia 1080 I got from vvjohn. I normally only buy EVGA 3 fan models. So my theory is, since this seems to be the default fan curve, is that this is how NVidia keeps the fan noise down. Sure enough, overriding the fan and setting it to 70% makes it considerably louder, and at 100% it wails.

A little experimentation allowed me to figure out that 78% fan speed was required to keep the temps at around 75 C. So I defined a custom fan curve that tops out at around 78% at 75C, and for safety jumps up to 100% at 81 C. Yes, a bit noisier, but I play with headphones on and I don't notice it.

For good measure I went into the mobo BIOS and bumped the fan curves up on the front and back case fans which are ultra silent 120mm Nexus fans. Even at 80% you can barely hear them. I made the curve much more aggressive to allow for better air flow.

I think this might explain why sometimes I would inexplicably get 10fps dips during gameplay. With the new GPS fan curve, my frame rate seems much smoother and more consistent. KF2 is now a rock steady 90 fps, where I used to get dips down into the low 80s.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Thu Oct 15, 2020 7:39 pm
by FlyingPenguin
Before and after. Notice the difference in the GPU clock. When the GPU hits 82 C it has to throttle back the clock.

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Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Thu Oct 15, 2020 8:09 pm
by Err
I have the EVGA 2 fan version of the 1080. EVGA has the card set to not turn the fans on at all until 42 C or so. I set a custom fan profile so it's at 10% idle and ramps up to 80% at 80C.

Since your card is a reference card, you should be able to find an aftermarket cooler. However, I doubt you'll be running that card in a few months once we get our hands on a 3080.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Thu Oct 15, 2020 8:53 pm
by FlyingPenguin
Ya. The card does it's job, and now I picked up a free 100MHz boost improvement by fixing the fan curve. It'll do fine until I replace it with a 3080.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Thu Oct 15, 2020 9:46 pm
by Key Keeper
Is it a Ti card?

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Thu Oct 15, 2020 10:42 pm
by FlyingPenguin
Nope. Just a stock GTX 1080 reference card.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Thu Oct 15, 2020 11:27 pm
by Executioner
wow. I never knew there was software to check temps and fan speeds. I downloaded the MSI Afterburner to check my desktop system.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Fri Oct 16, 2020 12:38 am
by Losbot
Good thing you realized that. Now you'll be happier with performance and not kill your card.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Fri Oct 16, 2020 7:23 am
by Err
Afterburner can also display temps in game through Rivatuner which should install with Afterburner. It will also do screenshots and video capture for most games.

Note that if you have a program crash when starting, Afterburner may be trying to hook it. You can add an exception in Rivatuner so it ignores the program. My "old" version of Vegas won't start unless I had an exception for it.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Fri Oct 16, 2020 9:48 am
by FlyingPenguin
Exec:
if you just want a simple monitor, GPU-Z will show you Temps and fan speeds, and not hook deeply into the OS like Afterburner.

Careful with Afterburner. You can accidently overvoltage and overclock without meaning to. It's interface is rather arcane, but there's lot's of good YouTube tutorials our there. The default skin sucks IMO, but there are several to choose from.

Since I have a second monitor, I just left Afterburner open on it while running the Valley benchmark and then I played a few rounds of Killing Floor 2, which used to have the wildest FPS fluctuations, to monitor Temps and fan speed.

Be aware that if you modify anything, like the fan curves, or the clock, you need to leave Afterburner running in the background or it reverts to the card defaults.

I've used Afterburner in the past for fan tuning. I had a card, like Err, that didn't start spinning the fans at all until it had warmed up quite a bit, and I prefer to have SOME airflow. I think the manufacturers are too conservative with fan curves in order to claim low noise levels.

I experimented with overclocking on the GTX760 once, but it wasn't worth it. All modern cards essentially overclock themselves dynamically with the boost clock, and it's not worth pushing them past that for the very minor performance gain, and added instability, unless you're going to upgrade the cooler or go liquid.

Re: Well my GTX1080 has been essentially underclocked due to the fan curve

Posted: Fri Oct 16, 2020 9:55 am
by FlyingPenguin
Good thing you realized that. Now you'll be happier with performance and not kill your card
Yeah, 82C is just about 180 degrees F and that's nuts. It was actually making the DP to DVI adapter cable, connected to the 2nd monitor, soft.