[SOLVED] Radiator space?

[Potato Joe]

I have a Threadripper 1950X cooled by a 420mm radiator and 2 GTX 1080 Ti cooled by a 280mm radiator. The GPUs reach 87C under load, which isn't unexpected given the heat load for a single rad, but I thought the CPU radiator would be more capable for a single component? How much heat does a 1950X generate? GPUs not overclocked, CPU running at 4GHz, lower than default voltage, and sits idle in the mid-60s. Waterblock is the EK sTR4 nickel-plated block.

 

[Darkbreeze]

Where is each radiator located and what orientation, intake or exhaust is each of them configured as?

 

[Potato Joe]

CPU radiator is on top of the case as an exhaust, GPU radiator is intake on the front. Fans are EK Furious Vardar 140mm, if that makes a difference

 

[Darkbreeze]

I'm assuming you ALSO have a rear exhaust case fan as well?

What is your case model?

What is your motherboard model?

 

[Potato Joe]

Motherboard is an Asrock X399 Taichi, case is a Corsair Obsidian 1000D. There is a rear exhaust fan, 140mm.

 

[Darkbreeze]

Ok, so are you on the latest BIOS version? Version 3.9? If not, it would be advisable to update. When updating, please be aware of the update notes on the BIOS updates page starting with version 2.3. You must update to version 2.3 BEFORE updating to any newer version.

Also, make sure you are on THIS latest version of the X399 AMD chipset drivers. You should update the chipset drivers to the latest version BEFORE updating to the latest BIOS version.

https://www.amd.com/en/support/chipsets/amd-socket-tr4/x399

Do you have additional intake fans in the front panel, or are the radiator fans the only front intakes?

Honestly, it might not be a bad idea to add a couple of extra intake fans and also a second rear exhaust fan. The reasoning behind it that I'm thinking is this. You have two 2080 ti's connected to the front radiator. That is dumping a lot of heat into the case so that the radiator for the CPU in the top has nothing but already hot air to work with.

Adding some additional front intake fans if your configuration can accommodate it, which I'm unclear on since I am not familiar with your front radiator configuration and whether it is blocking any or all of the additional fan mounting locations up front or not, would help to bring the overall internal temperature down somewhat so that the upper radiator has a lower mean temperature to work with. Because if, for example only, the internal air temperature is 60°C because the saturation is high from the twin 2080 ti loop, then the temperature on the CPU loop can NEVER be below 60°C. You can never achieve lower than ambient temperatures without phase change or refrigerated cooling.

So for our purposes, the internal case temp IS the ambient as far as the upper radiator is concerned. Whatever the air is in the case, that is the lowest the temperature of the CPU loop can ever be. The front loop can of course be as low as whatever the actual ambient temperature is outside the case, although in BOTH these instances, it is only theoretical that they could be that low. In reality, they would be at least five to ten degrees warmer than that because it would be rare or impossible to have 100% efficient cooling that allowed you to actually achieve ambient temp balance.

So bringing some additional cool outside air into the case that DOES NOT have to pass through the front radiator, will help to drop the internal case temperature especially if you also have some additional exhaust flow by way of a second rear exhaust since that case supports two of them. That will also help to reduce the internal case pressure so that the front fans don't have to struggle quite so hard against the probable high positive pressure conditions inside the case. Neutral or negative pressure conditions are favorable for cooling performance AND for fan bearing and motor longevity. The easier it is for your fans to operate, the longer they will last and usually the quieter they will run as well. They themselves will also run cooler that way, so that they are not contributing as much heat to the internal case temperature as well.

Just some thoughts. I don't think there is any magic bullet unless you simply have a pump that isn't working correctly on your CPU loop. Any idea what your maximum CPU temperature is? You state your idle temp but no mention of load temps and since those are far more important, it would be helpful to know.

 

[Karadjgne]

Instead of the standard dab of paste in the center, try covering the entire base of the block with paste instead. Hardware Unboxed did a thermal test on the TR 1950x and at a 4.0GHz all core OC got 88°C. After redoing the paste to cover the full pump area, temps dropped to 83°C. On a TT 360 Riing RGB. Since you have a loop, chances are good its a thicker rad and far better fans than the TT, so rad TDP is probably very similar. Both being somewhere around 350w for the 280mm, so well capable of keeping that cpu in check, even under duress. Use of the 420mm is overkill for the cpu alone.

I'd change the loop to a single loop, combine the 420mm with the 280mm. Share the loads. Seperate loops aren't doing you any favors.

 

[Potato Joe]

Load temps reach the high 80s in real world use but synthetic loads stay around 75 for some reason. What I was considering was replacing the single 280 with a pair of 480 rads, since the front of the case does not actually support any 140mm fan mounts (I mounted the rad diagonally) and put everything in one loop after cleaning the blocks out with a fine, soft bristle toothbrush. I was just looking for more economical suggestions before I go that route, because I also don't have any 120mm fans to put on the 480mm rads, and 8 fans plus 2 rads in a single purchase isn't cheap.

 

[Karadjgne]

DB, the way I read it, Op is saying sli 1080ti's on a 280mm rad, and the TR on a 420mm rad. 2 loops.

Both are pulling high 80's at load.

 

[Potato Joe]

GPU temps rise to thermal shutdown after about an hour when both are put under load.

 

[Karadjgne]

You aren't using enough wattage to need 2x 480mm rads. The 420mm + 280mm should be more than enough. Top card will pull @ 280w, bottom @ 200w, 180w from cpu. That's 660w roughly. The 280mm is @ 350w+ and the 420mm is @ 500w+. You've got 660w use, and over 850w capacity. You are covered.

 

[Potato Joe]

They are two separate loops, just to be completely clear, and as you've pointed out, I have 480W of heat on the GPU loop and only 350-ish W of cooling. Current max CPU temp is 89C. Worth mentioning, prior to the current setup, I had 2 420mm rads and the 280 with all components in a single loop in a janky setup on a bequiet dark base pro 900, with the extra 420mm rad mounted externally via the rear exhaust fan mount of the case and while the CPU was always running warmer than I'd like (low 60s idle, high 70s load) the GPUs never exceeded 50C under any load, and the CPU never hit 80.

 

[Potato Joe]

After checking Prime95's most recent version with all AVX instructions turned off, my CPU hit 92C after about 14 seconds running 4 threads. At 16 threads temps hit 85 before I canceled the test, it took about 30 seconds, but the CPU was downclocked to 2GHz automatically. 32 threads, temps took about a minute to hit 80C, CPU throttled to 1300MHz. Something is very wrong here.

 

[Karadjgne]

Yes. I'd say so. P95+ AVX might see 80's with all threads at 4.0GHz, but not on just 4. Might want to check paste, check the loop. Honestly I'd just redo the whole thing from scratch, checking every component for possible blockage.

 

[Potato Joe]

Yyeeeeaaaahhh I'm gonna take the blocks apart and clean them with a toothbrush once I have the extra rads, put everything in a single loop and call it a day. Still gonna use both pumps though.

 

[Potato Joe]

Alright, final response time. The GPU blocks were fine, no buildup, nothing I could see. The CPU block was dirty. The two cooling loops are combined into one with a 420mm rad and two 480mm rads. Temps at idle for all components are 42C or below. Under prime95 with AVX2 enabled the CPU hits 81C, and considering nothing else will ever make the CPU that hot, I'll take that as a victory.

 

[Darkbreeze]

AVX and AVX2 should be disabled when doing thermal testing unless you know you plan to run applications or games that are heavily dependent on them. But if that is accurate, and you don't have any offset configured in the BIOS for AVX, then that's a victory for sure.

 

[Karadjgne]

AVX is bad enough, AVX2 is downright brutal, and AVX-512 is a nightmare for a cpu. Not that you'd ever likely run into 512, but I'd still count it as a definite victory if you run full out and still barely pass 80°C with no offsets.