• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

CPU temp 50C under light load.

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

TheNoobCaker

New Member
Joined
May 13, 2016
Hello everyone. I just completed my first water cooling loop yesterday and started running some benchmarks and everything is running fine. However, I have noticed that whenever the GPU is under heavy/full load, the CPU temperature will increase even if the CPU is under little load. I'm not sure if this is normal with water cooling, but I haven't really heard of this before. Here is the way I have my loop set up:
  1. Reservior/D5 Pump(max speed) to GPU
  2. GPU to 140mm Rad(UpsideDown)(Exhaust)
  3. 140mm Rad to CPU
  4. CPU to 240mm Rad(Horizontal)(Exhaust)
  5. 240mm Rad to Reservior
Here are my specs as well:
  • i7 4790K @ 4.6Ghz
  • EVGA 980 Ti SC ACX 2.0(stock clock until I get this sorted out)
  • MSI Z97A Gaming 7
  • 16GB Corsair Vengeance @ 1600Mhz
  • Sentey 850 Watt PSU
  • Windows 10 Home
I have read that having a radiator upside down won't impact cooling performance but I thought I would mention it anyway. Also I am pretty sure it's not the thermal paste, as I can run CPU stress tests that never go over ~64C. I have recorded temps and %usage of both the GPU and CPU with MSI Afterburner during four different tasks.
  • Watching YouTube Video
afterburner1youtube.png
  • Running CPU-Z Stress Test
afterburner2cpuz.png
  • Running Valley Benchmark
afterburner3valley.png
  • Playing The Witcher 3
afterburner4witcher.png
 

Conumdrum

Member
Joined
Sep 15, 2007
Location
Small town Emlenton, PA
The CPU has to work a bit harder to process the GPU working. You also don't have a ton of rad for your setup. The GPU also warms the water when you stress it. A 1C rise in water temp is a 1C rise in CPU temp.

Perfectly normal.
 
OP
T

TheNoobCaker

New Member
Joined
May 13, 2016
The CPU has to work a bit harder to process the GPU working. You also don't have a ton of rad for your setup. The GPU also warms the water when you stress it. A 1C rise in water temp is a 1C rise in CPU temp.

Perfectly normal.

Ok. Nice to know I didn't mess something up. Although, when I did the CPU-Z stress test, shouldn't the temp on the GPU have gone up as well? And one last question, how much radiator space should I have for a system like this? The rads that I have now are 45mm thick.
 
Last edited:

Tír na nÓg

Member
Joined
Sep 19, 2015
And one last question, how much radiator space should I have for a system like this? The rads that I have now are 45mm thick.

I use at least 1x120mm rad per 100W TDP to dissipate.

In your case, you'd need at least 4x120mm (+/- 350W CPU+GPU on load).

Still, I'd feel more comfortable with a bit more raddage.
 

Lochekey

Senior Pink Member
Joined
Sep 13, 2015
You could also reverse your flow order to help prevent the gpu from effecting the cpu. Something like this,

Res/pump ->240 rad->cpu->140 rad->gpu


Note that doing this will not change the max temps your system reaches after the loop becomes heat saturated but it should help prevent the short term spikes from the gpu from effecting the cpu as much.
 

ATMINSIDE

Sim Racing Aficionado Co-Owner
Joined
Jun 28, 2012

Tír na nÓg

Member
Joined
Sep 19, 2015

Nebulous

Señor Senior, Senior
Joined
Oct 11, 2002
Location
The Empire State
I'd rather use a 500w by a confirmed tried and true brand like EVGA, Silverstone, or an Antec before I trust a Sentey unit.
 

ATMINSIDE

Sim Racing Aficionado Co-Owner
Joined
Jun 28, 2012
Sure, the model would help!

This one doesn't look bad either (never heard of this brand though...):

http://www.hardwaresecrets.com/sentey-sdp850-ss-power-supply-review/12/

Just because a brand, overall, is known for low quality PSU's doesn't mean they can't put out a good one every now and then.

I'd rather use a 500w by a confirmed tried and true brand like EVGA, Silverstone, or an Antec before I trust a Sentey unit.

This +1.
Sentey has a few decent (even good) units out there, but most are a 4+ year old design at this point and the vast majority of their lineup is crap.
 

Mr.Scott

Beamed Me Up!
Joined
Jun 9, 2013
Why are we picking apart a PSU in a water cooling/temperature problem thread?
 

GTXJackBauer

Water Cooling Senior Member, #TEAMH20HNO
Joined
May 22, 2011
Location
USA
Why are we picking apart a PSU in a water cooling/temperature problem thread?

:rofl:

It's ok Scott. Every bit helps. As the saying goes, if you see something, say something.

OP, your temps and usage look normal. Nothing wrong with what I'am seeing. The amount of rad is fine but if you want better temps, add more rad and try reversing the flow from GPU to CPU as Loche said. That will save you only a few degrees as CPU's are very sensitive compared to GPUs.
 
OP
T

TheNoobCaker

New Member
Joined
May 13, 2016
:rofl:

It's ok Scott. Every bit helps. As the saying goes, if you see something, say something.

OP, your temps and usage look normal. Nothing wrong with what I'am seeing. The amount of rad is fine but if you want better temps, add more rad and try reversing the flow from GPU to CPU as Loche said. That will save you only a few degrees as CPU's are very sensitive compared to GPUs.

Thanks for the replies everyone, even if we did go on about the PSU lol. I guess I'll reverse the order like yall were saying and see how the temps do then.