Log SMOL 4.2L - Fully watercooled workstation with RTX 3070 and 5900X

Hiraeth

Cable Smoosher
Original poster
Nov 20, 2020
8
9


This has been a long going design process. I began working on this years ago but haven’t come around to do it.
This has had some benefits, some parts have become more SFF friendly, and by revisiting my design I have shrunk
the case from 9.7 L down to 4.2 L, without losing any performance. (In theory at least).

I mainly use my rig for work, which includes heavy simulations, rendering and multitasking.
I like to game sometime, but when choosing between a larger case and a 3070, I chose the latter.

To get this to work I need to do a couple of things that has to do with temperatures.
I started out with making the assumption that most people overestimate the amount of cooling needed when water cooling.
This usually makes sense, bigger radiators isn’t that much more expensive and more fans does probably help to keep the noise down if done correctly.
At the same time, LTT showed us that while not satisfactory, it is possible to cool a 3090 on a 120mm radiator (66 degrees with full turbo).
This got me thinking. The 3090 has an average power consumption of 350W. The 3070 has an amazing performance at only 200W average.
That would potentially leave room for a high-end CPU.
The only thing I could not change size of was the motherboard, which became the starting point for about 20 iterations of different placements with different hardware.




When looking through cooling options I first opted out of water cooling because of the extra parts that would take up space.
I began looking at it again after realizing the thickness of the GPU is critical as it is hard to place somewhere where it fits.
After opting in to water cooling again, I began looking for radiators which is as large as the motherboard, but not larger. A 140mm radiator would be suitable here.

When this was figured out I had to find a suitable GPU. The 3070 FE was really the only alternative.
No other latest-gen GPU has a PCB below 170mm. Finding a 3070 FE is hard enough (I am yet to get my hands on one).
Finding a block for it is even harder. The blocks for the 3080/3090 FE versions are rather large and I would assume the 3070 blocks would be of equal size.
I decided I must make my own GPU-block to make this viable.

Specs:
- X570 of some sort, the flatter the better.
- 5900X / 5950X (Same TDP, can't really defend the extra cost for 5950X but would be cool for performance)
- 3070 FE
- 64 GB, 3600MHz RAM of some kind, probably Vengeance low-profile.
- 500-700W Flex ATX - PSU (been looking at a few options, but most are on sites I do not know the language of).
- CPU block/Pump/res combo, been looking at the Alphacool LT Solo, might be too thick.
- Some slim fan, probably a NF 12x15.
- A 140mm radiator.
- Case, SMOL, by me.

ToDo:
Order components for practical measurements
Tubing size test with 10mm ID and 6mm ID for differences in tempertaure and flow.
Fan test for radiator with regards to temperature
Get hold of a 3070 FE...
Design waterblock for 3070 FE.

Challanges:
Make sure 140mm radiator that is heavily covered by CPU block will be enough for cooling high-end CPU + GPU
Fitting it all in 4.2L and below, this number might rise or fall depending on any last minute design progress.
Making a block that will be slim and cool sufficiently with zero air flow.

I would love your input, whether it is ideas or something I've missed. I'm also aware of that 4.2L might be overconfident, but I need something to drive innovative thinking.
 

harveyy_sh

Efficiency Noob
Nov 14, 2020
5
1
The G Unique, I am not sure which one that is. It is the brick one?
I’m not sure but I think he has brickless psu’s that go over 600w.


I wish there was a 700w flex atx from reputable brand.
 

Hiraeth

Cable Smoosher
Original poster
Nov 20, 2020
8
9
I’m not sure but I think he has brickless psu’s that go over 600w.


I wish there was a 700w flex atx from reputable brand.
Exactly. I have no doubts these guys who make custom PSUs know what they are doing. But I also know that testing generally is a lot stricter in the industry.
 

paulesko

Airflow Optimizer
Jul 31, 2019
289
212
FSP have something that can fit your case

it´s only 500, but I guess it could be probably enough
or this one

if not, try with one of these server 1u psu. they are longer, but very very slim... you´ll probably will need to mod some things, but these are top quality

You also has the enhance version with 600w, and the variants, which have some sellers here in this forum (If I remember correctly). Enhance is a very reputable brand. I believe they manufacture silverstone power supplies
 
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Hiraeth

Cable Smoosher
Original poster
Nov 20, 2020
8
9
Dimensions?
Right now the outer dimensions are 216*173*112 = 4.185L . They might change depending on my thermal tests.
If my thermals will be alright I might be able to sink the fan and pump into the radiator, making it 216*173*107 = sub 4L
 

Hiraeth

Cable Smoosher
Original poster
Nov 20, 2020
8
9
Hardware just showed up at my doorstep!

First of all we have the motherboard, Gigabyte X570 I Aorus Pro WiFi



5900X also arrived, I went for the 5900X in the end. The 5950X would be cool for performance per liter, but not for performance per cost.



Mounted!



I also got hold of a Corsair XR5 140 Hydro Series Radiator. Hopefully this will fit my needs.
Below it is on top of the corrent cooler height. I am not sure which distance I need from the block to radiator, but I think a few mm will do.



Right now I am trying to get hold of a 3070FE for further measurements.
 
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Hiraeth

Cable Smoosher
Original poster
Nov 20, 2020
8
9
So this showed up! It has been a hassle to get hold of this one.



I feel bad about removing this cooler to watercool it...


Gorgeous



Also had the RAM show up. 2x32GB sticks for this one. Finally I will be able to keep all my tabs browsing the internet...



I will test this card out ASAP and hopefully get some good results of undervolting it!
 

Hiraeth

Cable Smoosher
Original poster
Nov 20, 2020
8
9
Been sick for the past days, taken a covid-test, but I have had some strength to chill out with building computer things.

Before I can take the GPU apart I need to make sure to know how flow is needed in terms of cooling. The pump is very weak, but it is the best I can fit. So I had to set up some thermal testing.



The Pump/CPU block will be the Alphacool Eisbaer LT,




To save some space I ordered a Noctua NF-A12x15,





As you can see this shaved off 15mm of the chassi height! About 0.55L saved!




I started making some base-line benchmarks using Cinebench R23 with a normal BeQuiet cooler. Went up to 74 degrees, with CPU power consumption reported at 115W. I tried using AMD master software for a quick undervolting which brought it down to 94W and a temperature of 65*C with sustained results.



I then put the loop together, using the 16/10mm tubing. The flow is horrible, which was not even enough to use the flow-meter. I measured by using a glass and I calculated the flow to be around 30L/h at most. This doesn't matter much as long as the temperatures are alright though. I fired up Cinebench and did the same testing. With stock settings it performed similarly to the BeQuiet cooler, at 72 degrees. When undervolting, and cranking the fan speed up to levels I was okay with in terms of noise, I did manage to bring it down to 61 degrees with sustained results







I do wonder how the pipe diameter might change the flow though. I was interested in using 8/6 mm tubing, to make it fit easier with push in fittings. I will do some more testing of this later this weekend. Below is an image for comparison.







And the push in fitting







Ordinary fluid dynamic formulas show that 6mm dia tubing should have 13% of the flow in a 10mm tube. However the flow might already be restricted by the blocks so much that the tubing size does not really matter.



Next update will be when I have been able to test the small tubing!
 

harveyy_sh

Efficiency Noob
Nov 14, 2020
5
1
Been sick for the past days, taken a covid-test, but I have had some strength to chill out with building computer things.

Before I can take the GPU apart I need to make sure to know how flow is needed in terms of cooling. The pump is very weak, but it is the best I can fit. So I had to set up some thermal testing.



The Pump/CPU block will be the Alphacool Eisbaer LT,




To save some space I ordered a Noctua NF-A12x15,





As you can see this shaved off 15mm of the chassi height! About 0.55L saved!




I started making some base-line benchmarks using Cinebench R23 with a normal BeQuiet cooler. Went up to 74 degrees, with CPU power consumption reported at 115W. I tried using AMD master software for a quick undervolting which brought it down to 94W and a temperature of 65*C with sustained results.



I then put the loop together, using the 16/10mm tubing. The flow is horrible, which was not even enough to use the flow-meter. I measured by using a glass and I calculated the flow to be around 30L/h at most. This doesn't matter much as long as the temperatures are alright though. I fired up Cinebench and did the same testing. With stock settings it performed similarly to the BeQuiet cooler, at 72 degrees. When undervolting, and cranking the fan speed up to levels I was okay with in terms of noise, I did manage to bring it down to 61 degrees with sustained results







I do wonder how the pipe diameter might change the flow though. I was interested in using 8/6 mm tubing, to make it fit easier with push in fittings. I will do some more testing of this later this weekend. Below is an image for comparison.







And the push in fitting







Ordinary fluid dynamic formulas show that 6mm dia tubing should have 13% of the flow in a 10mm tube. However the flow might already be restricted by the blocks so much that the tubing size does not really matter.



Next update will be when I have been able to test the small tubing!
What push in fittings are those??

Hope you feel better soon!
 

Hiraeth

Cable Smoosher
Original poster
Nov 20, 2020
8
9
Challenging project, good luck with it! :thumb:
Thanks!


What push in fittings are those??

Hope you feel better soon!
Those were just the first I could find, just took some 8/6 push-in fittings I saw on aquatuning. They work wonders! I was sceptical at first, but I can now show that fitting/tube size does not matter even at 6mm thickness. I just did the same tests as earlier today and I got the same results! 72 degrees in stock and 62 degrees with undervolt.

Test-setup

 
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