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First open loop: advice, knowledge, warnings?

I am in the mental debate stage - sort of knowing that this is the likely step to take.

I am doing mostly video work. Encoding/Transcoding, tensor based upscaling on the GPU and some light editing in Premiere. I do most of the work in batches.

I am noticing that the encoding and transcoding push my cpu, a 3900x, up to 80c with the occasional 85C spike. No OC at present, stock freq with a set voltage of 1.35 using a Dark Rock Pro 4 cooler.

My 2080 ti when doing upscaling workloads will report a GPU core temp of ~65C, but the memory modules can get as hot as 77C. The GPU is at stock, with a custom fan curve, I would like to OC it but I am hesitant given the temps for this work load.

I have used the EK loop configurator, and will probably be getting the whole loop from them. They are the only place that has a full block for my GPU that I have found and rather than mixing and matching parts, I can keep the costs down getting it from one place.

Other than an in-line temp sensor, that I can get from alpha cool, what else should I get/know?

I admit to knowing next to nothing about open loop cooling and the fittings give me pause; especially when it comes to T fittings and the placement of drain.

Another question re: fittings is, when using soft tubing, does using angled fittings make much of a difference; 45/90 degree fittings, or does it not matter the type of tubing they make your runs easier regardless?

This isn’t something I am buying tomorrow, and even if it were, it wouldn’t get to me pdq.

Can I share my EK configurator link or will a screen grab be better?

In-line temp sensors aren’t really necessary. I’ve been building my own liquid-cooled rigs for about 10 years and have never used one. Just make sure you can get enough radiator capacity in your case for the components you want to cool. The more the better so you can run the fans at a lower speed for less noise.

The fitting angles do matter even with soft tubing. If you try to bend a soft tube into a tight radius, then you could pinch the tube and restrict the fluid flow. Thicker wall tubing can bend more without deforming the tube. But you still need to plan out the type and quantity of fittings you’ll need. It’s a good idea to buy a few extra to give yourself some flexibility.

The drains are pretty simple. Put them at the lowest points of the loop. I have 2 in my system. My dual pumps are mounted on the floor of my case so I have one there. I have another in the drain port of the radiator mounted to the front.

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Thank you for a such a good reply.

I am beginning to feel more like I understand this.

What’s your case? Airflow and stuff, how is everything configured?
Also tried to let Auto handle vcore? And are you on the latest BIOS?

I’m using a Phanteks P600s, with 4 Noctua NF-F12 case fans configured for positive airflow; 3 at the front, 1 for exhaust.

I have tried auto for Vcore, it results in similar temps, but higher voltages, and I drop clocks on heavier workloads. For example, I was compressing blu ray files last night and I was running auto for Vcore, temps were averaging 83C with 88C spikes, and the clocks dropped all the way to base. I know that the frequency is temp related, which is why I am on the internal debate over whether to invest in open loop cooling.

I just checked the support page for my mobo, X570 Aorus Master, and I am on the latest BIOS; F11.

If I didn’t answer something, let me know. I may have misunderstood what you were asking for.

That is strange, that cooler is pretty beefy and from a quick look the case seems airflow optimized as well. Did you try a remount on the dark rock? What about fans, how fast are those running?

Yeah, I have remounted that cooler 4 times now. Such a pain in the ass.

3 times when I had it on my old mobo, an Aorus Elite, and the once as I transferred everything to the Master. Temps have always been consistent with the mount on the Master giving me better CCX deltas. I suspect that the Be Quiet silent wing fans do not have enough CFM to transfer the heat out fast enough.

I have all the fans running at max speed, except the gpus fans which are either on a custom curve or set at 85% depending on the work load.

Under ‘normal’ conditions the Dark Rock is a great cooler, but with batch processing it seems to hit its saturation point rather quickly and struggles to keep up with the load over time.

IDK, maybe I am not looking at this the right way?

When running your workload like that bluray compression, is that CPU+GPU work or pure CPU?
Also: GPU vertical or horizontal straight into the board?

Blu Ray compression is pure CPU; generally 10bit h265, sometimes 2 pass encoding.

The GPU workload is upscaling of SD files, typically DVD quality, with some VHS. It’s not terribly demanding, but it does take a long time and can generate a lot of heat - all depending on the algo used, the size of files, the target size for upscaling etc. 2-3 hours for a 20 min file, and 5-30 hours for full length movies.

When I need to format shift things in a hurry or to make a proxy copy for a rough edit, I will do GPU encoding.

GPU is not vertically mounted, it is straight into the board.

Here is a silly idea: Is there a way to drop from PCIe4 to 3.0 in the UEFI? Not just GPU but overall. I honestly have no idea if that makes any difference on the CPU side … but hey, right?

Oh, one other thing: What about RAM? Capacity, speed, CL? How about dropping speeds there? Shouldn’t make a difference in performance for that type of workload, right?

Yes I can make manual adjustments to the PCIe in the BIOS but cannot make any such adjustments for probably another 24 hours; batch is running.

I am running 32 GB of 3200CL16 RAM. it’s Corsair Vengence (CMK32GX4M2B3200C16). I picked it because it is QVL and when i was buying parts 3600 RAM was ridiculously expensive in my part of the world.

Honestly, IDK if dropping the RAM to 2666 would make any difference in that sort of work load. The only real difference would be the voltage to the memcontroller, yeah - 1.20v vs 1.35v; or am I not understanding something here?

The memory speed and IF speed are linked. Drop one and the other one follows. The difference in heat can be drastic because the memory controller and the infinity fabric are running cooler. If you can, try dropping to 2666 and log performance and temps.

My never-ending to do list has some new items for tomorrow. :grinning:

I have a pile of things to encode that I was going to do later today, while the GPU is batching, but I can wait until I (re)set to 2666 RAM timings to log any differences.

Thanks for the assist

Hey man, anything to make you jump through more hoops, right? :rofl:
Jokes aside I’m curious how this turns out myself.
Good luck.

EK usually makes ok stuff all round, with a few oopsies over they years, but they are rarely my favorite over the decade plus I’ve been doing it. That and their quality control has been slipping again in the past 1.5 year.

If I were to build a new loop from scratch today, personally I’d go:

Heatkiller IV CPU block. Not that chart topper in any particular aspect, but the relative comparison of price/thermal/flow is the most advantageous option as I see it. Optimus has better thermal but those worst flow I’ve seen in a long time, since like, Swiftech was still relevant. EK has the “Quantum Magnitude” that actually performs really well, but is stupid expensive, and the other from them are not so good. Heatkiller IV has 2nd in class in all aspects, instead of 1st in one or two classes but last in class in some other class.

Heatkiller IV GPU block. I’ve not seen any numbers for Optimus yet, but even then at over $200 that means it would be competing with the Aqua Computer Kryographics Next and that one isn’t worth the few % difference over the Heatkiller. Flow numbers are next to nonexistent for GPU blocks, I have to go to obscure German sites just to get comparison charts for thermal nowadays.

You said only EK makes a block that fits, are you sure? Non reference PCB? That sucks, they don’t do as well in that area.

Hardwarelabs SR-2 radiators. These are the best along with HWL GTX for really slow RPM fans. They also have the Alphacool style extra ports for extra routing flexibility, which, I have used as a way of making a really sleek and hidden drain and fill, even without using any extra fittings at all. I personally bloody hate t lines.

Monsoon Modular Reservoir System. It’s just so customizable and SICK looking. Speaking of a slick AF drain or fill, this has some pretty cool ways of doing that as well.

EK Dual PWM D5 pump. This comes in a nice custom dual top with lots of rubber vibration isolation. Simple choice, overkill maybe… probably. I used to run dual video card back when you know, GPU companies still gave a shit about that. Single suffices for most things.

Barrow compression and XSPC angled rotary fittings. This is where I would cheap out. God these suckers can be expensive AF. Over the years I’ve used so many types of fittings, I’ve never seen it to matter. The only thing that even can go wrong with them is the finish and the rotary kind can leak, but I’ve never had that happen with any of mine. Any brand rotary can leak if QC is off or if you put pressure on them parallel to the rotation plane. Thus, you want them to be under zero tension if you can mange it. If I felt baller and was going for pure looks, Monsoon Chainguns are still the hotness if you ask me. (They do visually synergy with the Monsoon radiator really well). EK has a nice feature where the inner surface of the fitting are milled like a hex screw so you can tighten therm with an allen key instead of using a coin (not that, it really makes any difference) like you do with the kind with slots cut in them, but they are overpriced unless you can get old stock of the previous models.

Non personally switching out the Monsoon reservoir for a simpler cheaper one, and whoever is selling the cheapest single D5 at the time is really the only changes I would make. Possibly res/pump combo thing.

I had some other things to say here Liquid cooling for EPYC - need advice.


My setup is exactly what you mentioned minus the motherboard. Ask me anything.

Here is a very brief summary of my testing this morning. As you can see I totally forgot to log the speed of compression from Handbrake. The output times were all roughly the same, within a few minutes on a 3 hour+ encode. I didn’t do the full encode just used the very large file as a dummy load to generate heat.

2133 mem
10 min - max 78C 4.1Ghz
2400 mem
10 min - max 79.5C 4.05Ghz
2666 mem
10 min - max 81.5 4.04Ghz

I have full csv’s for each run. I hate spreadsheets, but if required I can make them available.

AFAIK. I have an EVGA 2080 ti FTW 3 Ultra Gaming. I think i found one other block, but it’s out of stock; Bykski. Maybe there’s Barrow? I live in Canada, so it’s importation no matter who i decide on, and as I spread my order out over multiple vendors the costs go up exponentially as I have to pay customs/duties/taxes on each shipment instead of the one. Plus the ridiculous costs to ship here in the first place.

Thank you. That O11 Dynamic looks super clean.
My only questions still are the outstanding ones about T fittings and drains, it’s probably the layout that I need to fix in my head, but I am still in the mental debate stage; wrapping my head around this is better than buying and swearing later, yeah?

Just so we’re all on the same page this is the loop I ‘designed’ in the EK configurator. It doesn’t include any extra fittings etc it’s just the basic ingredients. Am I missing anything?

I would usually advise people building their first loop to keep it as simple as possible until you feel comfortable with designing a more complicated one, but dual pumps are nice to have. 2 pumps running at 50% are much quieter than 1 pump running at a higher load. Plus, you have some redundancy in case of a pump failure. It also means that your pumps are less likely to fail b/c they can be operated at lower rpm’s together thus reducing wear on the pumps.

I use 2 of the smaller DDC pumps running in series to increase the head. I have them set at about 50% so the rpm is constant and let the radiator fans on pwm adjust if the system gets to hot. Half a dozen fans spinning up a few hundred rpm is much quieter and less annoying than a pump spinning up to 3500-4000 rpm. If you have enough radiator capacity then your fans won’t spin up either. The loop I have now was originally designed to handle an overclocked i7 and 3 overclocked GPU’s. Like most people, I’ve abandoned multi-gpu so it runs whisper quiet. My FreeNAS box is louder.

Regardless, make sure you get a pump or pumps that are variable speed. PWM controlled or manual, as long as you can adjust it so it is running at a speed that is effective for your loop without running at full tilt all the time. PWM is more convenient since it’s easier to control in software.

Overall staying below 80°C seems about right for an air cooled system. Bummer that the memory speed doesn’t do more to the temps. I guess those are back to back to back, so the delta might be even closer.

I only have the one tee with a ball valve and I should have included another up high for bleeding because it will airlock. Not a huge deal since you can just lean the case around.

I’m not a huge fan of EK for a few reasons having stuck within their ecosystem. If I was building something new tomorrow I would look at other companies but thats my own personal beef.

On the topic of your configuration. Looks good, but I have a few thoughts. Where are you mounting the pump? EK has a bracket that will allow you to mount in 120mm fan locations or directly to a fan. I would avoid the splitters, or at the very minimum only use the 2 fan splitter because I’ve heard of the 3 fan splitters causing people to kill their fan headers. Depending on the fan that could end up popping fuses. I think you’re a little light on the radiator. I have the thicker rads in a 240 and 360 and still hit 75c with the loop saturated. Granted my fan speeds are a little slow but I’m not trying to go for a wind tunnel here either. I would probably skip the atx plug as most decent PSUs come with them and its not that hard to jumper but :man_shrugging:

Thats my $0.02. You should pay attention to what @Pawmaniac says. Dude knows his shit. I’m just a single build ahead of you here.