GPU temp problems

V4NT0M · 21 Apr 2016 at 10:59

Hey guys, need a little advice on my loop. Bit of a long winded synopsis but the more info the better eh. I have 2x 290s in crossfire in my loop and usually their temps are around 50 - 60 in a long gaming session. Recently I have been playing the division a lot which does not support crossfire so I've only been using one card.

I popped out of game the other day to notice that my GPU had actually hit 85 degrees. Cause for alarm no doubt. I had a little look around and tipped the case a bit thinking maybe there was a bubble stuck, but I was running extra volts so I dropped them down too. After that temps seemed still higher than normal at 70+. I tried running another game (GTA) which showed the GPU temp at 60 degrees so I figure there was some quirk in the division running my GPU hotter and figured I would look into that.

However since then even with no extra volts the division was starting to run the card to 85 degrees again. So I tried GTA again, I noticed two things however, fristly I was running GTA in crossfire and the temps were actually showing on the first card as 60-65 and the second card 40-45, an exremely unusual difference. I tried GTA without crossfire and it was running the card to 70 degrees. Not normal at all.

I ran a few other games in crossfire and tried a few different drivers to troubleshoot and had a feel about in the case, the the first card's block felt cool to the touch the whole time, but the second card felt warm as I would expect.

For now I have switched the video output so the main card is the second one, back in GTA it was running 40-45 degrees. So I'm of the opinion that there is a problem with the first block but not sure what.

So here's my logic: If there was a problem with the block such as microchannels being blocked then the block would get hot and not dissipate heat into the water. Therefore the block would be very hot and not cool.

If there was a problem with restriction in the first block I would also expect this to manifest higher temps in both cards as the flow rate would be less to both.

My thinking is that it may be a problem with the TIM and it's not transferring heat effectively from the GPU to the block. I'll be doing some more tinkering tonight but won't really be able to drain and dismantle until the weekend so hoping other people can give their opinion in the meantime.

I previously used GELID GC-3 on the card and if I'm going to take the block apart I'll have to replace that anyway so what to people recommend for TIM on the waterblock? I bought the gelid before I watercooled and seem to remember that it's really better at higher temps so guessing there may be something better at watercooling temps.

Thanks for reading if you made it all the way through

V4NT0M · 21 Apr 2016 at 17:07

Read a few other people using MX4 too, that works out well as I have some lying around.

V4NT0M · 25 Apr 2016 at 19:04

Right guys, a little more help needed.

I replaced the blocks at the weekend and things seemed better, however I did notice that when I was refilling the loop the flow rate seemed low, I took it apart again and checked the gpu blocks to see if there was any restriction there but they were fine. Temps seemed fine for a bit but then started creeping up again.

I think the problem is the pump...

When I originally built the loop if I turned the pump up to 4/5 it would churn the water up with bubbles as if it was too high and going any higher than 1/2 would not affect temps by more than a degree or so.

I did notice before I took the loop apart that it was no longer doing this but thought nothing of it at the time. It still doesn't do this now but instead when I have the pump at 1/2 temps are getting up to around 60 degrees, If I turn it up to 4 or 5 the temps now drop back down to around 46ish degrees.

Is it worth taking it out to give it a clean or is it just on it's way out and time for a new one?

V4NT0M · 26 Apr 2016 at 00:25

The bubbles didn't seem to be coming from anywhere, I think it was sucking them up from the top of the res maybe. Was difficult to say, but there weren't any bubbles coming up the tubing into the res (as far as I remember). As I said though it's not doing that any more. Currently have it on 4 and can't hear it so shouldn't be a problem.

I started using the top card as the main card again as the second card was actually pretty unstable, not sure if that's the same problem you had as when I bought it from the MM the original owner could not get it to boot into windows, I installed it as the second card no problem. When I used it as the main I had the same issues.

Did a good load of tipping this time to get rid of air pockets as there were plenty.

I am using this res:
https://www.overclockers.co.uk/xspc-acrylic-tank-reservoir-for-laing-d5-wc-172-xs.html

V4NT0M · 26 Apr 2016 at 12:48

I don't have a sensor for the loop, keep meaning to fit one when I clean or change but always forget.

I had another thought last night actually, I did add another rad to the loop a little while ago so not sure whether it's just requiring a bit more oomph to push the liquid through the loop. The new rad is mounted at the top so the liquid is going higher and through a rad at the top too.

I guess I'll just keep an eye on it for now, the pump does have to take the liquid through the cpu, through a 240 rad at the top, two gpu blocks and then a 360 rad which is mounted with the plug ports at the bottom. So in essence pumping the liquid to the top of the case twice.

V4NT0M · 3 May 2016 at 16:05

Thanks for the input guys, I have narrowed down the issue. After I cleaned the block last time the temps were fine but then began to rise from 45 to 60 again by the end of the week, the second card remained unchanged. So I took it apart at the weekend and drained it completely and replaced the Mayhems with DI water and so far it has been fine, holding at 45 degrees. Seems there was some gunk in my coolant I'm not entirely sure where it came from but the microchannels on the first card were trapping it all before it got to the second and causing restiction.

So I have ordered some more coolant, some tubing and some fittings that I couldn't get but really wanted when I added the new rad. I'll take everything out and give it a good clean. I've also got some new fans to add so it'll be a nice spring clean.

Evil-I said:
Are you running your GPUs in serial or parallel? I prefer parallel as its less restrictive.

I believe it's in parallel.

Evil-I said:
Have you flushed the loop with DI water and replaced the coolant?

Have you taken the blocks apart and cleaned them?

This is basically what I've done now, and it seems that was the problem.

As above not sure if it was the coolant was using Mayhems X1 and have ordered the same again.