Advice on air cooling dual 1080s in 600Q

I installed a second GTX-1080 in my 600Q case and now both are running too hot. The case has the standard single front fan and back fan. I'm looking for advice on whether to add a second intake on the front or add a second intake fan on the bottom (or both) to get the temp of the GPUs down. I am using this rig to fold so the CPU remains mostly idle.

 

The air coming off the rear exhaust fan is cool. The back slugs behind the GPUs are super hot. Seems like the case and current fan configuration is not getting the heat out of the top area. I've read reviews that the case is good on cooling so I assume it is something with the fan configuration.

 

Also the air coming off of the PS exhaust is cool as well

 

New to PC building and rather not get into liquid cooling if I do not have to.

 

Thanks,

Kof

The bottom is intended as exhaust.

Definitely need another intake, at least.

 

However ... more fans won't necessarily solve your problem. I'm going to guess that you have your fans connected to the motherboard and fan speeds determined by CPU temperature? If you are folding and not stressing the CPU, then the fans won't spin faster to provide the airflow that you need to cool those cards. You'll need an alternate temperature source to use as your control. It doesn't look like your motherboard has a connector for a temperature probe but you may be able to use the motherboard sensor; that's hard to say. It'll require some experimentation to see what temperatures fluctuate with the GPUs and what the ceiling should be.

Thanks for the quick response. I thought the bottom was intended for exhaust but then I saw that there is a magnetic air filter covering the bottom vents making me think it could be either.

 

I didn't think about the CPU temp controlling the fans. Give me something to go on.

You can use the bottom as either intake or exhaust, but that is not the issue at the moment. The inverted 600C/Q is an interesting design, but when it was released I was running SLI and I immediately wondered how it would fare with high GPU heat. I am not sure I want my PSU to be the exhaust conduit and there is not an easy way out except through active fan exhaust. You need to keep that back fan turning pretty good. The other end of this is changing the air out (faster case fan rates) is not going to be completely effective. You need to try and displace the air between the cards to moderate that hot spot. You probably want some speed on your front two intake fans and I would want something with a flatter blade and more focused flow. ML type fan versus AF140. If you can move a little air between the cards, that should allow it vent out the back.

Also, I think that you'll want the bottom for exhaust. You need to get cool air in there, sure ... but you also need to get the warm air out. I'm not sure if venting it out the back would be enough. Having the bottom with the rear exhaust would simply suck cool air in and then vent it out the back and allow the heat from your GPUs to rise through the system. You don't want that.

So I was mistaken. There are two 140mm fans in the front that came with the case. The inverted design means that the heat from the dual GPUs are blowing up into the top-back corner of the case. I replaced the top front fan with a Noctua NF-A14 iPPC-3000 and while it is a lot noisier the temp on the GPU closer to the bottom of the case has gone from 82C to 74C. The GPU up in that corner is still running 82/83C. I'm going to try the suggestion of adding a second exhaust fan in the bottom of the case.

 

Thanks again for the help.

It sounds like the lower card is getting some measure of direct cooling from the front, but as is typical, the top card is always going to be the hotter one. The GPU fans are blowing into their own circuit board, but it is the radiant heat that creates the hot spot. This can be difficult to manage. More exhaust may help, but you still have to displace the hot air trapped in the corner or it won't matter for GPU temp purposes.

So I ended up replacing the two front fans with Rosewill Hyperborea 140mm and used one of the original case fans as intake from the bottom. Using the Rosewill fans rather than the Noctua NF-A14 iPPC-3000 made the rig so much quieter and seems to be doing a good job reducing the GPU temps while I fold. The lower card is down to 70C and the trouble GPU is down to 76C. Thanks again for the help. I'll do a lot more planning with my next folding box I build.

My concern is that the bottom intake is still "pushing" the heat from the second CPU into that upper corner with little opportunity for it to escape the case.

So I ended up replacing the two front fans with Rosewill Hyperborea 140mm and used one of the original case fans as intake from the bottom. Using the Rosewill fans rather than the Noctua NF-A14 iPPC-3000 made the rig so much quieter and seems to be doing a good job reducing the GPU temps while I fold. The lower card is down to 70C and the trouble GPU is down to 76C. Thanks again for the help. I'll do a lot more planning with my next folding box I build.

 

Yeah, rather than pure airflow volume, you are looking for a fan that hits the GPU or the gap at the right angle. This is a bit hit and miss and one fan or another have have just right blade angle. I used to see this quite a bit with my rear exhaust fan. The higher airflow designed model was moving more air, but the flatter blade model would pull air right across the VRM modules and knock that down 5C. Pure airflow exchange rates are not the entire cooling process.

 

So, what is cooling the CPU? Is it a standard flush against the board fan? Or an air tower? What you do with the bottom fans may depend on that. I might be concerned about using the bottom as intake if it is pushing even more CPU waste heat up into the GPU zone. Bottom exhaust might get some of that out and create a stronger pull toward the rear corner where you want to drag the general case flow, away from the top right GPU corner.

The CPU (i5) is mostly idle. I don't fold on it. Doesn't do enough PPD for the heat it would generate. It is cooled with a Enermax ETS-T40F-TB 120mm CPU Cooler.

 

The design of the inverted case also has the PS intake up in that corner. I thought that would take some of that heat away.

OK, so vertical slim CPU tower. I would think the bottom as exhaust would give better results and help with the general goal getting warm air out of the corner, but it is simple enough to flip them around and see.

 

Your PSU might help move some air out of the corner, but an expense. First, a lot of PSUs have an ECO or zero fan mode so the fan doesn't spin at all half the time. Obviously no fan movement means no air movement. Turning the ECO mode off might keep the fan moving, but if your G2 is like my 1200 P2, then default fan speed when ECO is off is 100% and that is annoying. On my cases, it is not overly difficult to reach around and turn it on when needed, but that is not universally true. The second aspect is if you are pulling a lot of 50-60C air into your PSU, what temperature will its components be? You would probably run under 40C normally in cool environment. I wonder what the PSU exhaust temp is when affected by the GPU waste heat? No thermal software for EVGA, so you would need a temp probe or some other way to measure it.