Help with GPU 90C temps

[scibuff]

Hi guys, I'm having trouble with GPU temps in my loop. At idle the temp is ~30C (with ~22C ambient) but the moment I ran AIDA or RealBench stress, it shoots up to 90-95C. My CPU is at ~30C at idle and about 60-65 at load when OCed (4.7GHz with 1.26V) which is a good enough (at least for now). However, I imagine the GPU should really be in between 50-60C at load. I have bled the loop for over 36 hours and now tilting (even 90 degrees) doesn't release any more bubbles. While bleeding I followed the bubbles around and I think the flow is as good as it can be. While the GPU is at load, the backplate gets fairly hot but I can keep my hand on it so not too hot. I don't feel the rads getting any warmer (at least not that much that I would be able to tell). I have to temp sensors in the loop and after 15 min stress test they showed the H2O temp at 32C (but I only now realized both are placed right after the rads, before blocks).

 

I did test the mobo, cpu, gpu, ram, ssd with just stock air (outside of the chassis). GPU on air under load stayed at about 75C (IIRC).

 

The only thing I can think of for the culprit is that the block isn't set correctly. I used the pea method to apply the MX-4 paste but I worry the washers between the card and the block are preventing a good enough contact. The XSPC GTX980 Waterblock manual specifically shows washers added between the block and the card, should I try *not* adding them? 

 

Any other suggestions?

 

Thank you

 

==============

 

I have the following setup:

 

Mobo: ASUS Maximus Hero VII

CPU: 4790k @ 4.7GHz (1.26v)

RAM: Corsair Vengeance Pro 16 GB (2x8GB) DDR3-2133 CL9 (running at 1600)

SSD: Samsung 850 PRO 256GB

 

GPU: EVGA GTX 980 4GB ACX 2.0

PSU: Corsair 850AX

 

XSPC RayStrom

XSPC D5 170 Photon (pump+res combo)

XSPC RX360

XSPC RX240

XSPC Razor GTX 980 Waterblock

XSPC Razor GTX 980 Backplate

MX4 compound

 

Loop order: Res > Pump > RX240 (>drain with a closed valve) > GPU > RX360 > CPU > Res

T-sensors at GPU-in, RX360-out 

 

The loop pic is below

 

 

[Syte]

If your GPU temps are in the 90s on water I don't think you applied the thermal paste correctly, or the waterblock correctly. Or you don't have enough flow rate, though that doesn't seem likely as you have a CPU that is on the same loop keeping cool.

Also, use Unigine Heaven to test the card, not Aida64

[scibuff]

Thank you, I guess there's nothing else to do but to take the GPU block off and put it back in. Should i even attempt it without draining the loop?

[Aniallation]

Thank you, I guess there's nothing else to do but to take the GPU block off and put it back in. Should i even attempt it without draining the loop?

If it's flexible tubing I guess you could do it without draining the loop, depends how much coolant you have left laying around to refill with if you were to drain the loop. 

[scibuff]

It's just regular distilled water, I have about 10L around the house - I guess it will be easier & safer to drain it (although if I don't put the block correctly back again it would be pain to re-do)

 

anyway, thank you guys!

[scibuff]

OH yea baby, running the same bench/stress now takes my GPU to laughable 34C - when I took the waterblock off, the paste wasn't really spread (the shape it left wasn't really any bigger than the pea of paste I had put on the chip) which I think means that the washers were adding too much space in between. I didn't put them in this time and the block sits on the GPU nicely when awesome temps!

 

Thankyou!

[airdeano]

i'll always dry fit the GPU to waterblock, remove.

install GPU with TIM to block, remove.

install GPU, TIM and TIM pads to the block, remove.

this will show if there is contact area not covered, not enough application or TIM

pads might be too thick/thin.