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About 2 x GPUs and heat problems

Posted: Thu Jun 18, 2020 8:59 pm
by KtC
Recently I decided to upgrade my PC with 2 x 1070ti GPUs (from the second market) to use them for folding. You can imagine how much that was an improvement after switching from the single 1060 card. The power consumption increasedas well, but that was in range of my expectations. I also give it a try to use an Afterburner app to tweak my cards. After that the performance results were even better. That excitement lasted about a week.

After some time I realized two GPUs generate so much heat and are very loud. These were open-air GPUs (3 fans per card), so every hot air went into the case. They occupy 2.5 slots per each, mounted very close on the ATX board. Case, CPU, motherboard were very hot. Installing 3 fans at the front did not give me too much improvement. I started to extremely limit the GPU power with an afterburner. Things went better with like 60% of initial power. Even after that I worried my PC could cause a fire :) I finished up with returning those cards to the seller.

Now I am at the beginning point and still want to upgrade my 'rig'. Should I go with a single better performing card (like new RTX family) in the range of the same price as 2x1070ti used cards? Is it only way to build another PC to fold with a 2x1070ti setup and use them separately to not waste a calculation power? I am trying to find a sweet spot concerning I have already motherboard with 2 x PCIe x16.

Re: About 2 x GPUs and heat problems

Posted: Thu Jun 18, 2020 11:10 pm
by JimboPalmer
I confess I have been ebaying towers for each graphics card.

I use an HDMI switch on video.

Re: About 2 x GPUs and heat problems

Posted: Thu Jun 18, 2020 11:19 pm
by bikeaddict
I bought used HP Z240 and Dell T3600 workstations that come with large power supplies and 6-pin PCIe cables to install GPUs in. I run them with the side panel off on an old desk in the basement where the noise and heat aren't a concern. They are plugged into an ethernet switch that is plugged into a wifi range extender with an ethernet jack. They run Linux and I can SSH into them on my internal network and I have FAHControl set up to admin them.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 1:09 am
by MeeLee
The best bang for the buck, that could compete with 2x GTX 1070, is a single RTX 2060 KO.
It's by many considered as the fastest card for your money.
Of course, the 2070/2080 (super, non super, or Ti) are faster, but cost a LOT more too.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 2:11 am
by kiore
There are a variety of ways to deal with multi GPU set ups and the heat issues; run in the open either by removing case side panel and lying the rig down on the other side so the heat escapes upwards, by running totally in the open on a test bench or similar, or by liquid cooling using hybrid or full water cooling syetems.
Some of these will not fix the noise issue, but using a liquid cooled radiator does remove most of the heat from the case interior by directly exhausted outside of the case environment.
The suggestion for upgrade of getting a single more powerful card is valid, however if you become a mad serious folder (seems a risk) you will next be looking at adding another powerful card in that vacant slot and you are back to scratch but probably worse off as the new powerful cards will be even hotter.
Even the best case and case fans do not anticipate dealing with the heat generated by multi gpu folding, the super flow case fans that exist will be noisy, really if they are not noisy they are not pumping enough airflow. I think people frequently underate just how hot cards get when right up against each other, in the past I have built 4 dedicated 4x GPU and 5 x 2 or 3 gpu, but this has become harder and harder over the years as cards become multislot. Now I only run multigpus 24/7 folding when I have at least one of the cards liquid cooled with an external radiator. Other people in other circumstances may have different experiences, but jamming 2 or 3 high performance cards next to each other is a recipe for overheating.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 3:49 am
by Mxyzptlk
I’m running 2 2060’s in one computer. The upper one runs at around 64c and the lower one at 54c. Fan noise is minimal but I am power limiting them with MSI Afterburner without much ppd loss. I found that my case wasn’t very airflow friendly even though I had 2 140mm fans in the front. I modified my case with a 140 x 280 hole in the front of it and mounted a magnetic filter there. That made all the difference and I’m running an AMD 2700X with a Noctua Air cooler as well.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 6:28 am
by foldy
I found best cooling for 2x GPUs next to each other is to have a closed case but side panel provide 2 case fans in parallel to GPUs, blowing the GPU's hot air out. Other case fans at bottom or front blow cool air in. That helps GPU cooling more than just an open case.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 7:47 am
by HaloJones
Image

A GTX1070 and a TitanX powered by a G4400.

Liquid really is the only way with dual gpu

With single, you can make any card into a hybrid liquid cooled card with an NZXT G10/G12 and a used AIO.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 2:06 pm
by markdotgooley
Mxyzptlk wrote:I’m running 2 2060’s in one computer. The upper one runs at around 64c and the lower one at 54c. Fan noise is minimal but I am power limiting them with MSI Afterburner without much ppd loss. I found that my case wasn’t very airflow friendly even though I had 2 140mm fans in the front. I modified my case with a 140 x 280 hole in the front of it and mounted a magnetic filter there. That made all the difference and I’m running an AMD 2700X with a Noctua Air cooler as well.
I don't know what I'm doing wrong, as with a similar setup (two 2060s) the upper one runs near 80C at load and the lower over 70C... lots of fans on the case but maybe misplaced...

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 2:34 pm
by kiore
markdotgooley wrote:
Mxyzptlk wrote:I’m running 2 2060’s in one computer. The upper one runs at around 64c and the lower one at 54c. Fan noise is minimal but I am power limiting them with MSI Afterburner without much ppd loss. I found that my case wasn’t very airflow friendly even though I had 2 140mm fans in the front. I modified my case with a 140 x 280 hole in the front of it and mounted a magnetic filter there. That made all the difference and I’m running an AMD 2700X with a Noctua Air cooler as well.
I don't know what I'm doing wrong, as with a similar setup (two 2060s) the upper one runs near 80C at load and the lower over 70C... lots of fans on the case but maybe misplaced...
Note that Mxyzptlk writes "but I am power limiting them with MSI Afterburner" . I am surprised it is the upper one that is hotter is usually the other way around, is the CPU cooler blowing heat onto it?

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 2:44 pm
by kiore
Halojones, that a very tidy set up I am jealous. You can use hybrids for a dual or even a triple GPU set up although you start to struggle on where to put the radiators on a triple and when I ran a triple hybrid rig it was in the open with the 3 radiators lifted above the GPU on a home made frame. On a double hybrid inside a case I placed the lower radiator in the CPU exhaust spot and reversed the CPU cooler direction and the upper cards radiator went into the top of the case, even better would have been to use a sealed CPU cooler liquid circuit and exhausted it at top of case too (if you have 2 fan spots on top which I did) but with both gpus exhausting heat outside the case it didn't matter too much that the cpu aircooler blew it around inside the case. The reason I didn't put the lower card's rad in the top instead is that the tubing wasn't long enough to reach. I have a hybrid conversion kit for my RTX 2080ti which I have been meaning to install for the last couple of weekends, maybe this weekend will be the one to do it. I must say that every time I go to do it I see the first step is "remove 20 small screws" which as a first instruction is a little daunting but the process itself looks relatively easy if you get organized and keep all the pieces safe for reassembly.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 4:55 pm
by MeeLee
markdotgooley wrote:
Mxyzptlk wrote:I’m running 2 2060’s in one computer. The upper one runs at around 64c and the lower one at 54c. Fan noise is minimal but I am power limiting them with MSI Afterburner without much ppd loss. I found that my case wasn’t very airflow friendly even though I had 2 140mm fans in the front. I modified my case with a 140 x 280 hole in the front of it and mounted a magnetic filter there. That made all the difference and I’m running an AMD 2700X with a Noctua Air cooler as well.
I don't know what I'm doing wrong, as with a similar setup (two 2060s) the upper one runs near 80C at load and the lower over 70C... lots of fans on the case but maybe misplaced...
It'll depend on a few factors,
1- No one gets 60C or below without first setting the fan speed to 100% (or close to). Quite often setting them just below being annoying in loudness, as long as it's faster from the auto settings can save you several degrees! (in my case, upping the speed to 80% is almost inaudible, and cools sufficiently).
2- Many people cut power to the Nvidia GPUs. They're tuned for maximum performance. If you tune them like a mobile GPU, you can often save between 40 and 60% of power, with less than 2 to 10% performance!
3- Of course getting ambient temps down is a big part as well. For many people, who run their GPUs in an enclosed PC case, more intake fans are recommended. Others just open one side of the case, allowing the GPUs and PC internals to exhaust the air inside the room, which is potentially even better than many case fans.
A third option is to duct the air, which is the most efficient. Use spare materials like paper, tape, to create contraptions that will rout the heat out the back, and supply fresh air from the front. Slightly better than the above 2. I usually try to focus the hot air on the back of the PC where also the PSU exits the hot air.
And often put the PSU upside down, so it'll suck hot air from the CPU out the case, rather than have it use outside air to keep itself cool.
If your PSU has 25 to 50% higher power handling than you are actually using, this setup will work fine!

Another is to run your system in an open bench (motherboard horizonal, GPUs mounted vertically). This is a big improvement!
Or, do what I do, use PCIE risers, and mount the top GPU horizontally, while the bottom GPU is mounted vertically on the motherboard on an open bench.
That way the top GPU isn't restricted in getting fresh air by the bottom GPU.
Additionally I use a box fan, with a hepa (or you can also use a paper) filter behind it.
This allows me to run 2080Ti GPUs at 220W at temperatures below 70C at 85F ambient. and sometimes they drop as low as 48C, depending on ambient.

Sure, there are other options (like have an AC unit blow over the system), but the cost of keeping an ac unit cool your pc might cost more than the folding itself on electricity.

For most people, lowering the power, and playing around with some tape, fan speed, paper or cardboard ducting, can give great efficiency improvements!
While the GPUs run slightly slower because of capping the power, they also gain speed for running lower in temperature.

Most people who report temps below 60C, prefer triple fan designs on their GPUs.
If triple aren't available, they go with dual fan designs.
But the single fan designs are often not good enough to cool GPUs much beyond 100W.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 8:38 pm
by KtC
bikeaddict wrote:in the basement where the noise and heat aren't a concern
Unfortunately not an option to run my setup outside. I believe this are a very good condition to keep the hardware cooler.
MeeLee wrote:a single RTX 2060 KO.
Though about KO before I acquired 2x1070ti. My concern was about 2x fan cooling may be some limitation to run them 24/7 (also more noise).
kiore wrote:by removing case side panel and lying the rig down on the other side so the heat escapes upwards
I tested that scenario. That was the best setup I could do with my PC case, to keep these cards working cooler (@stock). Now I think additional mesh would make that setup even dust secured. Seems the 'budget friendly' option too.
foldy wrote:side panel provide 2 case fans in parallel to GPUs, blowing the GPU's hot air out. ... That helps GPU cooling more than just an open case.
That seems an even better option if the case does not have a glass panel.
markdotgooley wrote:with a similar setup (two 2060s) the upper one runs near 80C at load and the lower over 70C...
With 2x1070ti @ stock I noticed 84C (higher card) and about 75C (lower card). The CPU gets more heat as well. To keep them running cooler I limited power with MSI Afterburner to 50% and 30%. That gave me about 71C/71C on both cards. Probably the MB was still in high temperature stress between two cards. The 2060 seems to be less TDP (and better performer?), maybe more easy to control temperature in x2 setup.

My MB has only 2 x PCIex close to each other.  I saw motherboards with 3 x 16 PCIex slots. Maybe setting up two cards in 1'st and 7'ts slots would give them more breathing room for 24/7 running. But never saw such setup, seems to be a quite exotic. Custom liquid cooling looks very nice too from temperature perspective. But I don't think I am ready for such a big upgrade to my PC. I would lean toward a single card + AIO.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 9:39 pm
by markdotgooley
I stopped doing CPU folding on any cores of the 6-core Ryzen 5 CPU (was using 4 cores for CPU projects).

The temperatures of the GPUs (2060, 2060KO) went up.

Adding fans usually makes the temperatures of the GPUs go up, too.

If I cooled these blasted GPUs with liquid nitrogen, their temperatures would go up. I'm convinced of that now.

Re: About 2 x GPUs and heat problems

Posted: Fri Jun 19, 2020 11:30 pm
by kiore
How are you controlling the temps on the cards? I really recommend power limiting as a first step and looking at what the fans are really doing on an like MSI Afterburner.