Question Liquid Cooling Temp High

Jan 30, 2019
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Specs: i7-8086k 5.2hgz delid liquid metal paste inside and on top.
Gigabyte AORUS GeForce RTX 2080 Ti Xtreme WATERFORCE WB
GDDR4 3000mhz 32gb ram
EKWB RGB 360 kit
Prior to adding the 2080ti into my loop my cpu temps where: ~30c idle, ~40 to 50 c during benchmarks. After adding the graphics card into my loop my cpu temp increased to: ~30 to ~50 idle and up to 72c to 78c during benchmarks.
My GPU temp is varies from 30c to 47c depending on overclock or not. Not overclocked, what I usually run, I get about 35c.
I was wondering if I added another 360mm rad to my loop and get a new case(mine wont fit another one) that allows more fans as well, will my get close to temps before?
 

Eximo

Titan
Herald
I would ask if it needs to be that cool? 5.2Ghz at 78C during benchmarks means it is usually cooler than that? So how cool do you want it to be?

Adding more radiator should reduce temperatures, but I doubt you will see 50C. To be honest I wouldn't have expected 50C under load for a CPU without some seriously cool water or something. Was this a cold start or after letting it saturate the cooler for a bit? Ambient temperature really low?
 

Chrushop

Great
Mar 2, 2019
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Sounds fine to me aswell, time to stop benchmarking and use it. You're below 80C so that's good, benchmarking is about the most stressful thing you can do to your PC - you're typically smashing both CPU and GPU at the same time just for the sake of it. even intensive rendering typically uses either the GPU or the CPU.
It would be easier to add more fans to each radiator you do have installed in push/pull config. I've done that to my 9900k and just run them super low RPM to have a quiet PC.
Getting a whole new case just for an extra radiator for a PC that's not throttling seems a little over the top, GPUs have way higher temp limits than CPUs too. Could you tack on a 140mm or 120mm Rad to the rear case fan? even that would do something with fans on each side of it,

But you might have the money and just not care i.e. do you just want an excuse to rebuild and do a new loop? Then probably just do it, I prefer 280mm radiators because they have a surface area only marginally less than 360mm rads i.e 360x120=43200mm^2 and 280x240=39200mm^2 so you're losing 4cm^2 by going to a 280mm rad but getting beefier fans which can push heaps more air and run slower.

edit removed typo
 

Eximo

Titan
Herald
I also use 280mm radiators for reduced noise. But I was under the impression that 120mm fan/radiator have higher static pressure and are preferred. The radiators also typically have denser fins, so they really have more surface area per area. Also better for thicker rads.

I'm fairly happy with 55C absolute maximum on the GPU and low 80s spikes on my CPU (which itself is a pretty mediocre example of a 7700k, but still running 5Ghz)
 

digitalgriffin

Distinguished
Specs: i7-8086k 5.2hgz delid liquid metal paste inside and on top.
Gigabyte AORUS GeForce RTX 2080 Ti Xtreme WATERFORCE WB
GDDR4 3000mhz 32gb ram
EKWB RGB 360 kit
Prior to adding the 2080ti into my loop my cpu temps where: ~30c idle, ~40 to 50 c during benchmarks. After adding the graphics card into my loop my cpu temp increased to: ~30 to ~50 idle and up to 72c to 78c during benchmarks.
My GPU temp is varies from 30c to 47c depending on overclock or not. Not overclocked, what I usually run, I get about 35c.
I was wondering if I added another 360mm rad to my loop and get a new case(mine wont fit another one) that allows more fans as well, will my get close to temps before?
As you found out, GPU's can generate significantly more heat than CPUs. A lot depends on how you have your loop setup.


If you do this, I would recommend a T Splitter between the two radiators instead of running them in series due to how thermal conductivity and Newton's law works. Plus it will lower your pump drag which means your pump will flow easier as only half the flow goes through each radiator lowering back pressure.
 

digitalgriffin

Distinguished
I also use 280mm radiators for reduced noise. But I was under the impression that 120mm fan/radiator have higher static pressure and are preferred. The radiators also typically have denser fins, so they really have more surface area per area. Also better for thicker rads.

I'm fairly happy with 55C absolute maximum on the GPU and low 80s spikes on my CPU (which itself is a pretty mediocre example of a 7700k, but still running 5Ghz)
Popular misconception. It all depends on fan RPM and it's blade design and intended use.
 
Jan 30, 2019
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As you found out, GPU's can generate significantly more heat than CPUs. A lot depends on how you have your loop setup.


If you do this, I would recommend a T Splitter between the two radiators instead of running them in series due to how thermal conductivity and Newton's law works. Plus it will lower your pump drag which means your pump will flow easier as only half the flow goes through each radiator lowering back pressure.
But this would only work if they are perfectly next to each other. Splitting would cause water to follow the path of least resistance. I will be mounting one on top and one on front of case. This will mean most of the water will go to front of case because it has the least resistance going from the graphics card. This in turn should would make cooling inconsistent or make the 2nd rad near useless.
 

Eximo

Titan
Herald
Popular misconception. It all depends on fan RPM and it's blade design and intended use.
I suppose it may have changed as well. I did some quick checking and it seems most standard radiator designs keep the fin density between 120mm and 140mm designs.

I may be conflating this with decreased fin density as radiator thickness increases and that 120mm varieties perform better under that circumstance.
 

Eximo

Titan
Herald
But this would only work if they are perfectly next to each other. Splitting would cause water to follow the path of least resistance. I will be mounting one on top and one on front of case. This will mean most of the water will go to front of case because it has the least resistance going from the graphics card. This in turn should would make cooling inconsistent or make the 2nd rad near useless.
That doesn't seem to be the consensus amongst enthusiasts.

Putting radiators in parallel reduces flow rate through the radiators but decreases flow resistance. Water should stay in contact with the radiator slightly longer and cool slightly better as well.

In a closed system, it doesn't matter all that much if your pump is up to the challenge.

That said, it can make for some odd tube runs. I've not tried it myself.
 

digitalgriffin

Distinguished
But this would only work if they are perfectly next to each other. Splitting would cause water to follow the path of least resistance. I will be mounting one on top and one on front of case. This will mean most of the water will go to front of case because it has the least resistance going from the graphics card. This in turn should would make cooling inconsistent or make the 2nd rad near useless.
You can run series. Running parallel will grant you modest gains if set up properly. The exact mathematics of which depend on too many variables and math to explain here. But adding a second 360mm I would make sure darn well you are running a DDC pump.

Or

Put in a second loop.

I deal with fan, and coil ratings every day practically. (But on a much much larger scale.)
 
Jan 30, 2019
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digitalgriffin

Distinguished
Where did you get this information. Everywhere I look I see radiators provide minimal resistance. Blocks, fittings cause the most resistance. I have minimal fittings. The only extra I have is a t splitter for draining.
Most of the back pressure is pushing liquid through microfin channels. Your main problem 10:1 is not enough flow rate
I was tryna ng to keep that from getting worse. Buy to know for sure i would have to see your loop setup.

But dont discount the radiators when it comes to flow restriction. You're essentially doubling the number tubes per circuit while maintaining a high flow rate.

I have the calculators here. Its easy enough to demonstrate how you are affecting head pressures based on tpc and flow rate using the same surface area fin pattern copper tubes and brass headers and percent glycol (propylene or ethylene) and 14fpi aluminum corrugated fins of .08". To get the most accurate numbers though i would have to cut open a ek block and measure the tube profile, relative humidity (sensible rating) air temp and air density and flow rate.

Or you can buy a bykski flow rate meter.

Ddc pumps and distribution blocks exist for a reason.

When i say i deal with this stuff on a daily basis i wasnt joking. I also write ai programs for machines that design themselves and design circuits for ai sensor nets.
 
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Jan 30, 2019
18
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10
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Most of the back pressure is pushing liquid through microfin channels. Your main problem 10:1 is not enough flow rate
I was tryna ng to keep that from getting worse. Buy to know for sure i would have to see your loop setup.

But dont discount the radiators when it comes to flow restriction. You're essentially doubling the number tubes per circuit while maintaining a high flow rate.

I have the calculators here. Its easy enough to demonstrate how you are affecting head pressures based on tpc and flow rate using the same surface area fin pattern copper tubes and brass headers and percent glycol (propylene or ethylene) and 14fpi aluminum corrugated fins of .08". To get the most accurate numbers though i would have to cut open a ek block and measure the tube profile, relative humidity (sensible rating) air temp and air density and flow rate.

Or you can buy a bykski flow rate meter.

Ddc pumps and distribution blocks exist for a reason.

When i say i deal with this stuff on a daily basis i wasnt joking. I also write ai programs for machines that design themselves and design circuits for ai sensor nets.
So now, what would be better on temp. If i buy a second pump rez and make 2 loops gpu rad on top and cpu rad on front of case. Will that potentially give better temps or should I just get ddc pump forget the one I have now. I think if Iwanted to do the first I would need a fan header splitter. I need to know this soon to order and have it here on time
 

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