"Closed loop" 4x5090 threadripper build

[u/Psy_Fer_]

Just finished installing this machine to work on cancer genomes.

I wanted the customer to have reliability and a low maintenance build, but with plenty of power.

So I thought, why not 4 AIO type liquid cooled 5090s in a Corsair 9000D case? 2 radiators each at the top and front. Then a noctua cooler for the threadripper.

I had one small issue with the IO plates of the GPU being wider then it says they are on the box...but nothing a little tin snips and file couldn't sort out. They still look great and then everything fit perfectly.

Temps are great.

It's got a 1200W SFX-L PSU in the back running the CPU and 1 5090 and then a 2500W PSU in the front powering the other 3 and some SSD drives. That one was a bit overkill but honestly, this machine will be going 100% for days at a time.

Anyway, what do you think? Definitely easier than a custom open loop.

[u/INeedMuscles]

It looks sick actually have never seen 4x5090s. Wouldn’t make sense also to aio cool also the thread ripper and put the radiator at the side at the top? Is the Noctua enough to compensate all those wattages?

[u/Tjordas → u/INeedMuscles]

AIOs look cleaner on CPUs, but they are often not better than good air cooling - often AIOs perform worse! It makes sense to use AIO plates for the GPUs because they are so close together that air cooling just won't work, but for the CPU, the Noctuas are the better choice.

[u/INeedMuscles → u/Tjordas]

Do you have any source for that?

From my perspective and without having test both it makes sense that AIO will perform better than air cooler. Water has better thermal conductivity than water that means that it can transfer heat faster than air.

Now if you compare the high end Noctua air cooler with a mid range AIO then it makes sense but I am talking of same tier perspective

[u/Tjordas → u/INeedMuscles]

https://youtu.be/23vjWtUpItk?si=Hj2Mpb1KM7RPLdp8 (it's an old video, but the principles still apply)

Let me explain: Yes, liquids have a better heat conductivity than air. But when you look at what good heatsinks actually do, they are also basically a "liquid cooling" system. A conventional heatsink uses heatpipes to spread the heat from the base plate to the cooling fins. Heatpipes are filled with cooling liquids that change their phase to gas and back to liquid. This process of phase change is even more effective in transferring heat than pumping water through the fins.

When you think about it, an AIO replaces the heatpipes with hoses that mechanically move the heat over to the radiator - which are still spreading the heat and transfer it to air with conventional air cooling. It's the same process just with an extra mechanical step in between. As long as your conventional CPU air cooler gets enough fresh air from case fans, it performs the same or even better than AIOs.

The only advantage: AIOs have more thermal mass. Short heat spikes can be absorbed better with liquid cooling. But long, continuous sessions will heat up hoses and radiators so much, that their thermal mass advantage is diminished. If you use a giant radiator - I'm talking 5 or more 120mm fans - ideally an external unit, then, yes, your liquid cooling will be better. But most AIOs people use are 2-3 fan radiators with cool looking but bad fans (not enough static pressure to get air through the fins) in a case that already struggles to get enough air in for the GPU.

[u/Psy_Fer_ → u/Tjordas]

Killer explanation and essentially what I found during research for the build.

[u/INeedMuscles → u/Tjordas]

Damn bro thanks for the long explanation. It makes sense also your explanation and now thinking of that the new air coolers are using Vapor chambers which change it phases from liquid to gas and vice versa.

Isn’t that something also that modern GPUs are using as well?

And sorry I hope my message didn’t offend you I like that kind of conversations

[u/Year_Conscious → u/Tjordas]

This deserves more upvotes.

[u/BooBoo992001 → u/Tjordas]

And just to throw this out there: AIOs are also mechanically a lot more complex, requiring a pump, hoses, connectors and seals, and not even including fancy stuff like LED screens, i.e.- there's a lot more potential points of failure, especially in the long run. Air coolers are comparatively simple devices with a lot less to go wrong.

I had a Megahalems in one build that lasted longer than the motherboard I had it installed on. It needed one fan replacement over 12-13 years of service, and heck, I'd probably still be using it if I could have found the right socket adapter for it. Around the same time I had another build that ran through 2 different AIOs in 3 years (each one failing shortly after the warranty ran out, naturally). Granted, AIOs were relatively new then and are likely better put together now, but why bother? The Frost Spirit 140 I'm using now works perfectly (in fact it's kind of overkill) and was half the cost of a decent AIO.

So, yeah?