Solved Need advice on cooling graphics cards in SLI.

[Omegaman007]

I just purchased another GTX670 2GB (2 fan ASUS) to go with the one that's been in my system (3 fan Gigabyte Windforce). Both cards do rather well thermally in the Valley benchmark with the Gigabyte reaching 59C and the ASUS 63C when they're in the box alone. Things become uncomfortably warm when I hook them up in SLI as they are extremely close together and there is little room for the Gigabyte (top card) fans to blow its air out. When in SLI the Gigabyte hits 77C and the ASUS 67C. The first time I ran it in this configuration the PC crashed during the benchmark. Afterward I increased the speed on the two front intake fans and it was able to complete the test multiple times.

I attached some photos of the rig and would like some suggestions on what I can do to cool the top card. I don't think putting the ASUS on top would work because it's the warmer of the two cards to begin with, has a metal fan shroud (which could short the back of the Gigabyte), and the longer Gigabyte needs the space up there.

Fan setup is as follows:
2 fans in the front sucking air in over the HDs. They are on a manual fan controller.
1 side fan blowing air in between the power supply and the graphics cards, also on a manual fan controller (should it be blowing out?)
1 fan blowing air through the CPU heatsink (CPU_FAN control)
1 case fan blowing air out of the case on the other side of the CPU heatsink
1 case fan blowing air up and out of the tower (2 position speed switch)
1 bottom mounted power supply blowing air out of the back of the tower

 

[ShamrockRig]

Dust can be a prime example of overheating mate, give it a good hover out, i know one cards brand new but if the other has alot of dust on it then it could be blowing it around the case, apart from that, liquid cooling but i have seen similar setups run cooler when under stress, im not so sure, il leave it to the guru's on the site Anyway good luck

 

[smarteyeball]

Things become uncomfortably warm when I hook them up in SLI as they are extremely close together and there is little room for the Gigabyte (top card) fans to blow its air out. When in SLI the Gigabyte hits 77C and the ASUS 67C. The first time I ran it in this configuration the PC crashed during the benchmark. Afterward I increased the speed on the two front intake fans and it was able to complete the test multiple times.

Tbh, heat shouldn't have been a factor. I had a tri 670 sli setup and the top and middle card were quite happy running in the mid/high 90's. 77c shouldn't be an issue. (aside from not hitting the full boost clock speed)

1 side fan blowing air in between the power supply and the graphics cards, also on a manual fan controller (should it be blowing out?)

You can certainly try reversing the fan - but typically the side is always 'cool air in'.


Short of upgrading your case fans to ones that push more air, unfortunately there isn't a whole lot you can do. Partly because of the gigabyte dumping heat into your case, but mostly it's just how SLI is when two cards are sandwiched together.

Mine were windforce models as well and I actually placed a 120mm on top the primary card right over the backside of the gpu core - but it may have net me a whole 1-2c difference if that.

You could try to tidy up the cables and shove them more into the drive bay area to create less of a wind flow blockage from the two front fans.

Maybe add another 120mm fan behind the cards and remove that last top bracket to make a small "exhaust".

Create a custom fan profile with afterburner/Precision X to increase the cards fan speeds if you haven't already done so.

With SLI and sandwiched cards - noise and heat are always going to be a factor.

 

[Omegaman007]

Thanks for the suggestions guys. I'll give the insides a blast of air and a vacuum. I noticed quite a bit of dust on the side fan blades so I think I need to put a filter in front of it... any suggestions for something I can sandwich in there? I was thinking of maybe getting some spacers to get the fan closer to the graphics cards too. I wondered if one of these EVERCOOL SB-F2 Case Fan - Newegg.com might help but I'm tight for room in the case as is. I don't know why MB manufacturers don't leave more space between there graphic card slots.

I've read that some people wedge something like an eraser between the two cards, but since I occasionally move my computer, I'd rather use a a sturdier method, but one that will still easily let me remove the cards if I need. Have to come up with something.

Yeah, I was thinking <80C should be OK also but the way the PC crashed was very unusual. The screen went blank and everything locked up... even the power button would not work. I had to flip the switch on the power supply. It's only happened once so I guess I'm not going to freak out over it.

Thanks again for the suggestions and if you think of anything else please let me know. Peace!

 

[smarteyeball]

I noticed quite a bit of dust on the side fan blades so I think I need to put a filter in front of it... any suggestions for something I can sandwich in there?

People use a lot things from fine mesh to panty hose. I've used the panty hose method before and it does work - however it does block some air flow. It's a trade off.

I was thinking of maybe getting some spacers to get the fan closer to the graphics cards too.

You'd need to make sure the fan 'overpowers' the air coming out of the gigabyte. Place it towards the rear to get as much cool air over the memory and VRMs (Voltage regulators. These can get quite hot too)

In fact when I mentioned heat shouldn't be an issue, I forgot about that aspect. So while the core temps are fine, other areas of the card (basically near the power plug area) are susceptible to excess heat.

I wondered if one of these EVERCOOL SB-F2 Case Fan - Newegg.com might help but I'm tight for room in the case as is. I don't know why MB manufacturers don't leave more space between there graphic card slots.

Never actually used one. Some have claimed it makes a difference, others disagree. Plus there's the noise to consider.

Slot spacing was a big factor in me choosing my board. But I agree, the layout for the majority of boards is pretty damn tight.

I've read that some people wedge something like an eraser between the two cards, but since I occasionally move my computer, I'd rather use a a sturdier method, but one that will still easily let me remove the cards if I need. Have to come up with something

.

The wedge method does work with varying degrees of success. It's not a magic bullet though unfortunately, but every degree helps.

Depending on what you wedge in there, it can be pretty secure. An eraser shouldn't shift with movement if wedged tight enough.


Are you running the cards at stock speeds, or overclocked?

And your CPU cooler - can the orientation be changed so the CPU fan is 'on the bottom' so it's basically blowing up and out through the top exhaust?

 

[madspec]

You can water cool those things if you want.

NZXT makes a pretty nifty bracket Kraken? G10 - NZXT

You can use several closed loop water coolers like the NZXT Kraken X40 or the Corsair H90.

I have 2 x GTX770 and the temps on air are good, 25 idle and 70 at maxload. I did order the NZXT brackets but they are BO, waiting and waiting.

 

[Omegaman007]

I noticed quite a bit of dust on the side fan blades so I think I need to put a filter in front of it... any suggestions for something I can sandwich in there?

People use a lot things from fine mesh to panty hose. I've used the panty hose method before and it does work - however it does block some air flow. It's a trade off.

I was thinking of maybe getting some spacers to get the fan closer to the graphics cards too.

You'd need to make sure the fan 'overpowers' the air coming out of the gigabyte. Place it towards the rear to get as much cool air over the memory and VRMs (Voltage regulators. These can get quite hot too)

In fact when I mentioned heat shouldn't be an issue, I forgot about that aspect. So while the core temps are fine, other areas of the card (basically near the power plug area) are susceptible to excess heat.

I wondered if one of these EVERCOOL SB-F2 Case Fan - Newegg.com might help but I'm tight for room in the case as is. I don't know why MB manufacturers don't leave more space between there graphic card slots.

Never actually used one. Some have claimed it makes a difference, others disagree. Plus there's the noise to consider.

Slot spacing was a big factor in me choosing my board. But I agree, the layout for the majority of boards is pretty damn tight.

I've read that some people wedge something like an eraser between the two cards, but since I occasionally move my computer, I'd rather use a a sturdier method, but one that will still easily let me remove the cards if I need. Have to come up with something

.

The wedge method does work with varying degrees of success. It's not a magic bullet though unfortunately, but every degree helps.

Depending on what you wedge in there, it can be pretty secure. An eraser shouldn't shift with movement if wedged tight enough.


Are you running the cards at stock speeds, or overclocked?

And your CPU cooler - can the orientation be changed so the CPU fan is 'on the bottom' so it's basically blowing up and out through the top exhaust?

Those are some good suggestions, I especially like the idea of moving the CPU cooling fan by 90 degrees. I'll definitely check on that. I also have another CPU cooler that I could try. Right now I'm not happy with the CPU cooling solution; the cooler is huge so you'd figure it should be good enough, and I've tried using different thermal compounds but it still runs hotter than I would like. I run the i920 at 3.8GHz, if I try to run it at 4GHz it hits over 80C and the PC gets unstable. This is under 100% load on all cores (using Pi stress test). Runs perfect at 3.8GHz with CPU temp at 78C (same load). These were all from tests before I put the second gfx card in.

Although both the gfx cards overclocked by about 100MHz alone (I didn't try going higher), I have not attempted to overclock them in SLI because of the temps. The top card with throttle once it hits 75C anyway and I'm assuming they run synchronously when in SLI mode so trying to OC the bottom card probably won't give any improvements (that's only my assumption, I have no tried doing it).

What do you mean by rear of the gfx card? Over by the PCI power connectors or by the HDMI output side?

Man, I'll probably get funny looks if I go to the store asking for pantyhose... maybe I'll try dryer sheets first.

As for the liquid cooling it looks like a nice solution but I don't have much room in the case and I'd rather not spend that kind of coin on this rather old system.

 

[Mellon Head]

Thanks for the suggestions guys. I'll give the insides a blast of air and a vacuum.

Blast of air only. Save the vacuum for the floor and the furniture. It's a bad idea to put a vacuum wand into a PC as they generate a lot of static electricity. They make special vacuums just for that type of thing, but they are small and cost a bit of money. If you aren't using one of those, then keep the Hoover away from the PC.

 

[smarteyeball]

if I try to run it at 4GHz it hits over 80C and the PC gets unstable.

That could be due to insufficient vcore, RAM, etc When I stressed my i7 920, I'd let the core temp get up to ~95c during prime stress testing.

Although both the gfx cards overclocked by about 100MHz alone (I didn't try going higher), I have not attempted to overclock them in SLI because of the temps. ---(that's only my assumption, I have no tried doing it).

Overclocking the cards can add around 5c-10c to the temps (depending on OC)

In SLI the top card will run ~10c-20c higher because of the restricted airflow anyway.

You can OC the cards independently if you disable Sync in Afterburner/Precision X - The cards are happy to run at different speeds.

What do you mean by rear of the gfx card? Over by the PCI power connectors or by the HDMI output side?

Yep, the PCI plug end. Between the HDD cage and the bum of the cards, flowing over the cards to the rear of the case.

Man, I'll probably get funny looks if I go to the store asking for pantyhose... maybe I'll try dryer sheets first.

Lol, been there had the looks. Tbh I got an even funnier look when I said it was for the PC

As for the liquid cooling it looks like a nice solution but I don't have much room in the case and I'd rather not spend that kind of coin on this rather old system.

Yeah, you'd have to have external radiator which doesn't help portability.


The only other thing I could really suggest would be a larger case/more air and if your board allowed - the cards in slot 1 and 3 using a 3-way or extended bridge (like mine is setup). I sacrificed x16/x16 for x16/x8 To allow a slot in between my cards.

Or if you are handy with tools - mod the case. Cut some more holes for more/larger fans. (I'm not handy with tools so I just use a full size tower)

The one plus about spending coin on a case is that you can always reuse the new case in a future build.

 

[Omegaman007]

The only other thing I could really suggest would be a larger case/more air and if your board allowed - the cards in slot 1 and 3 using a 3-way or extended bridge (like mine is setup). I sacrificed x16/x16 for x16/x8 To allow a slot in between my cards.

Do you know if you lost any performance moving to x16/x8? I'm not sure if that's on option with my MB but I may look into it. Will check on the CPU fan relocation tomorrow also.

 

[Layback Bear]

I start off simple.
Cable management. Those cables are blocking most of the air coming from the front fans.
If possible you could also remove the front cages if you are not using them.
Without moving things around I don't see anyway of getting air in and out of that case.

It would be helpful if you would post you system specs as per this
Tutorial by Brink.
http://www.sevenforums.com/tutorials/180324-system-info-see-your-system-specs.html

Look at my specs at the lower left of this post and you will get a idea of all the information that would be nice to have.
Make sure you let us know what power supply is being used.

Could you post a site showing what case you are using?

Their is more to using SLI that just installing another card.

 

[Layback Bear]

Very seldom do mismatched video cards work well.
They should be exactly the same.

 

[linnemeyerhere]

For sure I would look into a new case with cable management area behind mobo. Here's a Corsair 400R that's cheap enough but lets things breath.

 

[Faladu]

My suggestion would also be a bigger case since yours is pretty over-crowded.

Decked out like Layback's case for your extreme heat situation.

I myself have stayed away from overclocking and multiple video cards, but if I did it, definitely would have to spend quite a bit extra to protect it since the amount of heat is so much higher than a simple system, and heat is the enemy of electronics.

 

[Layback Bear]

Thank you linnemeyerhere for the pictures.
As the pictures show better than words you must have a well organized case in order to get proper air flow. Getting proper air flow will also help your cpu air cooler do its job.
It might take a new case in order to run two video cards cool.
We can help with the selection if need be. Their are many good cases in various price ranges. As you can see the Corsair 400R is a good workable case for not to much money.
The proper power supply is a must x-2 running SLI. We can also help with that if need be.

Omegaman007 I and others are not saying don't run SLI. Many do and like it but their are things that have to be taken into consideration when doing so. Or you will go from happy single video card computing to very painful dual video card computing.

Letting us know what system you have will help us help you.
------------
Nice build linnemeyerhere. Thanks again for the pictures.

 

[linnemeyerhere]

No worries Jack you know I love taking pictures, funny though what used to load here on SF with ease now is timing out so I'm having to reduce them by 50%.

 

[Layback Bear]

I don't know what you mean by timing out.

 

[Mellon Head]

linnemeyerhere, that is one beautiful case. Well done.

 

[linnemeyerhere]

The picture file size requirements must have changed as I'm having to reduce them to not time out when downloading to SF's server.

 

[Mellon Head]

The picture file size requirements must have changed as I'm having to reduce them to not time out when downloading to SF's server.

Are you using Firefox? I had to switch from using Firefox to IE when on this forum because FF kept timing out on me, and would only load half menus, etc. No problems with IE so far, though I much prefer FF.