High temperatures when hybrid rendering

I hope someone can give me some advice on what to do. When Hybrid rendering in Vray Next (that means full load on CPU and GPU's) I can't seem to keep the temperatures under control. After 15 mins of rendering the temperature of the Threadripper rises to 85 degrees (and it seems it keeps slowly rising). I know that's 10 degrees under the limit according to AMD, but it's a bit higher than I'd like it to be. GPU's don't get over 60 degrees, so that's fine. Water temps rise to 45 degrees, which seems a bit high to me.

When I render on CPU only, the temperature stays under 70 degrees, which is also fine with me, I know this CPU is a hothead.

 

Things I tried: reseated the CPU block, reapply thermal paste, and I used Thermal Grizzly compound since the beginning

Reversing the fan on the back of the case: had no impact whatsoever.

Messed with the fan curves, it helps a 2 degrees when I put the fans on full speed, but the noise becomes unbearable of course, it actually barely changes beyond 1000 rpm, besides that I also built this machine to be quiet.

Increasing the pump speed matters the most, but right now it's already running at 4700RPM. So I now wonder if I should split the loop, because I guess a second pump wouldn't help much.

 

System Specs: TR 3970x, Aorus xtreme trx40, 4x RTX 2080ti, 256GB 3200 mem, and there are 3 Gigabyte PCI gen 4 nvme drives installed, and I know these run hot too, but readings say they don't get over 50 degrees.

 

Cooling: 1x XR5 420mm rad, 2 x XR7 480 rads all with ML fans in pull orientation, 1 ML 140mm fan in the back of the case. XC7 CPU block, XG7 blocks for the GPU's

 

Attached a pic, don't mind the cable management and missing leds here and there, will fix it when it works properly.

What's your vCore on the ThreadRipper?

What I've noticed is that enabling Precision Boost Overdrive (PBO) on the ThreadRipper3 will pour on additional vCore as long as you have the overhead to manage the heat. And, since you do, that's what it's going to do.

Well, if I understood correctly, this is your current fan orientation (picture: a)?

 

 

If yes, this is not ideal fan orientation, because when the air goes through front radiator, it becomes warm, then that warm air goes through the top radiator. Better orientation would be (picture: b)

 

This fan orientation is actually recommended by Corsair (picture: 1000d)

 

I hope this will help you a bit.

Edited February 2, 2020 by kuca poso

I was about to write the coolant does seem high for that radiator set-up, until I opened the picture and then realized it does say 4 x 2080 ti. I do think you are going to want to split the GPUs into their own loop and you do have the space. If the coolant temp is 45 and the Ryzen CPU temp at 85C, I don't think you can do much better than a 40C coolant to CPU differential without really limiting your clocks. Dropping the coolant temp by 10C would put you back at 75C, all else being equal.

Maybe I am wrong, but it looks like he is going into the output of the cpu block

It does look like the CPU block is set in reverse flow, but that should be a 0-2C penalty. However, being directly inline after 4 GPUs likely costs a lot a more than that.

Thanks for all the replies,

 

@DevBiker, PBO is off, but I'll see what happens when I adjust the vCore in the bios, in Ryzen Master it shows max 1.32 - the vCore actually goes down to 1.144 when rendering

 

@kuca poso, thanks, but that's not how it's set up, all the fans on the rads are exhausts.

 

@acemaniwa871 yeah I noticed kinda late it was in reverse flow (was because I mounted it according to the manual on the motherboard and then actually tubed it differently), but I thought a few degrees wouldn't matter that much

 

@c-attack, I was thinking of splitting the loop indeed and adding a radiator on the back of the case, just wondering which radiators I should attach to what.

Edited February 2, 2020 by damnengineer

I think I'll just order an extra radiator, fans and pump, connect the CPU to the back rad and top rad and the GPU's to the front radiators.

 

I'm a bit surprised of how much hotter the 3970x runs than the 2950x

I don't know much about AMD, but 32 cores is going to heat up quite a bit. It's a 280w cpu. Man that's a lot of power! And the fact you are trying to cool 4 RTX video cards. I think this warrants as much rad as you can get and I think in in this case, loop order might matter. I think you are correct in what you are going to do. I really hope this corrects your issue. But I think no matter what, that cpu is gonna get warm. There is just a lot of cores there. If you get hwmonitor from cpuid, I am not sure if it will tell you or not with the amd cpu. But on mine it tells me core temps, along with package temp. If those two are far off, you may find that the IHS isn't making good contact with the cpu. This may not be the case. It's just an idea to check.

 

But as I said, 32 cores that can use 280w is a lot to cool.

Edited February 2, 2020 by acemaninwa871

Keep in mind what you are witnessing with the "slowly rising CPU temp" when doing the GPU renders is the coolant temp continuing to increase and thus the CPU temp as well. The CPU only render gives a better idea of the true voltage based heat at max load and you can test that any time with a CPU only stress test to see.

 

Almost everyone would have better CPU temps in their custom loop when under mixed load if their CPU/GPU were on separate loops, although that calculation is normally 165W or so vs the 300-350W from the GPU. It's funny to say, but your TR is small potatoes at 280W. That's less than a single Ti, let alone 4.

 

In terms of ideal design, you might get the lowest possible CPU temps by using one of the 480s on the front. The remaining front 480 and top 420 can handle the GPUs. That would effectively handle the CPU and you likely don't care if the GPU temps are 62 vs 66C. Not sure if the rear 2x120 has more value as a free intake/exhaust. From a tubing stand point, I can see why you would like to use the dual 480s for the GPUs and the top 420 for the CPU. However, if you dump the front waste heat in, we can expected that liquid temp to be above 40C still and thus the exit air temp from the rad will also be 40C+. That then becomes your intake air temp for the top CPU rad. Effectively, you are still transferring the GPU heat penalty over, this time by air instead of water. In a normal 1:1 system, that might not be so bad, but here we have clear evidence that the liquid temp is going to be quite warm.

 

I suppose this also could be addressed by running the top as intake, but I really feel you then need to run the front as exhaust and that is not as attractive for most people.

Thanks guys, to be clear, the front is already set as an exhaust, so I assume my initial idea will work. According to Corsair, it seems all rads should be exhausts. I had to triple check that, because I'm used to creating an airflow.

 

I know the cpu is peanuts compared to the gpu's, but they manage to get rid of the heat much better.

 

So I guess I'll just get an extra pump and rad (just to be sure) and see what happens. Just a quick question, can I reuse the coolant I have to drain? It's only been in a few days, I know that sounds a bit cheap with all the stuff I put together, but I don't like to waste things either if it's not necessary.

 

Thanks again for all the advice, really appreciate it since I'm new to custom loops.

Edited February 2, 2020 by damnengineer

Ok, if you’re already past the front fan direction hurdle, then top 420=cpu, front dual 480 GPUs as is makes sense. I would skip the rear 240 until proven the 420mm can’t handle the TR, which seems very unlikely.

 

Yes, you can recycle the coolant. Makes sense when your system uses nearly 2L per fill.

Thanks c-attack, I decided to order the 240 rad anyway, I'm also pretty sure that the 420 could handle it, but it won't harm to add an extra rad either I suppose. And I don't feel like redoing this another time. I have the fans for it already anyway.

Well, ultimately the exhaust from the 240 becomes the intake air temp for the 420. Since those will be the same temp, it may not give you the return you would like. For example, if the coolant temp is 30C in the 240mm it’s exhaust temp will also be about 30C. That then goes over to the 420mm rad where the coolant is also 30C. Then you are pushing 30C air through a 30C radiator and it then how much heat can it remove per pass? It shifts the effective cooling work over to the 240. I wonder if it would be cooler without it? Best case still the same? Another option would be to top intake with front and rear 240 as exhaust. That would flip things around and the 420 is the prime worker with the 240 now less consequential. Since the gpu coolant loop will be warmer, it doesn’t face the same dilemma.

Good point, but according to the earlier corsair guide I should use all the radiators as exhaust, but somehow that doesn't appear logical to me, since you don't pull any cooler air in anymore. But say if that's the case then the air should go out. I'm not sure what that will do with temps in the case itself of course. I also like your last idea, once I get my components in, I'll mess around with it and just see what happens.

If you have high water temps it means your water blocks are doing good job. dT of about 35-45°C is perfectly normal.

 

You don't have block seating issues, you have heat dissipation issues.

 

I would highly recommend to set all you fans to exhaust mode to dump the heat out of the case. If you have one rads to pull or push fresh air in and other rad set to pull air out of the case you are essentially nullifying the effect of second radiator and you're actually having worse temperatures than without that last radiator. Trust the build guide, you have no reason not to. The air will find it's way into the chassis.

You're effectively dumping 1.5kW+ of heat, 85°C on the CPU is actually impressive. And also don't worry, 85°C is well within CPU spec.

Good point, but according to the earlier corsair guide I should use all the radiators as exhaust, but somehow that doesn't appear logical to me, since you don't pull any cooler air in anymore. But say if that's the case then the air should go out. I'm not sure what that will do with temps in the case itself of course. I also like your last idea, once I get my components in, I'll mess around with it and just see what happens.

 

In a limited 1 block/radiator kind of analysis, you can get slightly better performance by having slightly cooler intake air on that side of the radiator. However, the reality of multi-radiator multi-component systems is that things need to work together. Radiator size and the ability to place it usually trumps other things, like the top part of the case being 2C warmer than the front rail.

 

The other thing is total wattage matters. Someone running an AMD 3600 at 65W TDP can the stick their AIO radiator wherever without much consequence. 4 GPUs and a few dozen CPU cores is something different. You would prefer that heat is dumped directly out of the case. The CPU might be manageable, but the GPUs have too much effect on everything else. Those really need to be exhaust. You have a lot of internal air volume to work with. A small case might get its internal temps warmed quite a bit by RAM, motherboard VRM, capacitors, etc. That's not so much of an issue in the 1000D. You can take a temp check of the area up top, but I don't think you'll find much air temp difference between outside the rear and top internal. If so, then there is no reason not to exhaust the top 420 for the CPU and leave the back 2x120 as direct cooling for the MB plus normal unhindered intake.

 

That is the other thing that worries me a little. If you did put a 240mm on the back as intake, it will limit the amount of air you can bring into the case. The radiator is a substantial hindrance to airflow.

@tiborrr I know 85 degrees is within spec, but I let it run for 2 hours and it started throttling and reached 95 degrees. I'm not comfortable with running it at high temps like that, since I sometimes have renders that take more than 24 hours. The temperature of the liquid just keeps rising. I figured if I had seating issues, the CPU would get hot and the water not.

 

@c-attack I didn't put anything in the back yet, extra components arrive today. I'll first try to add that rad as well, set it as an exhaust and make a dual loop. Guess we'll just see what happens because sometimes practice is different from what I might expect. I also expected that the configurator was correct in suggesting components but it clearly is not working out that well for my usage.

 

I wonder if someone from Corsair could weigh in on this, if the configurator is basing this on long term full load on all the components or not.

Or whether simply putting the CPU first in the loop would help, I see machines like the Bizon V6000 which actually have the CPU before the GPU's.

Hi!

Like I said, you have heat dissipation issues. I would advise against adding that radiator and first make sure all fans are blowing air out of the case. I have also removed filters on my build on front and top because you don't need them when you have fans in exhaust mode.

 

Loop order doesn't matter, it's a 1-2 degree difference between components at best and at very high power load.

 

I think it is a genuinely difficult task to create a template for every case and every possible hardware configuration. It’s a place to start and then see how your individual needs, whether technical or aesthetic fit into that design. You have a high TDP CPU and 4 GPUs. I wouldn’t say that is typical and fits into a cookie cutter shaped plan.

 

If you were going to keep things in a single loop, we might examine order a bit more. With 1 cpu and gpu the order is irrelevant (the aforementioned 1-1.5C). However, the single largest gain in cpu temp will be gained by going to a dual loop and separating it from a potential 1200W of GPU energy. A 420mm radiator with that cpu should keep your coolant delta to less than +10C above ambient. You are reaching +20C now and that is where the 10C lower temps on the cpu come from.

Hi!

Like I said, you have heat dissipation issues. I would advise against adding that radiator and first make sure all fans are blowing air out of the case. I have also removed filters on my build on front and top because you don't need them when you have fans in exhaust mode.

 

Loop order doesn't matter, it's a 1-2 degree difference between components at best and at very high power load.

 

 

All my fans were blowing outside of the case already. I only did tests with reversing the rear fan (without rad) but that didn't matter that much, but the fans on the rads have always been pointing outward. Anyway, I set up a dual loop now, it's leak testing, so we'll know tomorrow.

The filter idea is a good one, gonna try that as well as soon as it runs.

That's quite a lovely machine tiborrr.

 

@c-attack I understand that you can't make a template for everything, but according to the configurator it should even handle it with one radiator less. I had it run it quite a bit longer still, at some point it reached +35.

 

I think this is all happening because most people are not using hybrid rendering, so it's either CPU or GPU, I understand that putting 100% load on both CPU and GPU for a long period of time with hardware like this is asking for a bit of trouble. And yeah to be honest, temps where quite good when I only used CPU or GPU.

 

Thanks for all the help and advice, I'm learning a lot during this whole custom water loop process and it's all really quite fascinating.

Well the results are in, with a dual loop I managed to keep the CPU at max 79 degrees and the CPU's at max 65 degrees with a 3 hour render.

I did put the 240mm radiator in the back as well in the end so I can't really tell if it helps or not, since I didn't try it without it, but I don't feel like taking it apart again to try it out.

 

Again, thanks for all the input, much appreciated!

Well the results are in, with a dual loop I managed to keep the CPU at max 79 degrees and the CPU's at max 65 degrees with a 3 hour render.

I did put the 240mm radiator in the back as well in the end so I can't really tell if it helps or not, since I didn't try it without it, but I don't feel like taking it apart again to try it out.

 

Again, thanks for all the input, much appreciated!

 

i know this post is a little old, but is that an xc7 block on that 3970x or the correct xc9 painted? Either way, as pretty as the corsair block is, it's just too small for threadripper. I have an xspc raystorm neo tr4 i will be installing on my 3960x when it gets here. Single 2080ti though.