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

[Hiraeth]

 

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.

[Hiraeth]

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.

[Stygian Zenith]

Wow! Love the progress so far. Look forward to see more.

[Hiraeth]

4 hours ago, Stygian Zenith said:

Wow! Love the progress so far. Look forward to see more.

Thank you! Will have more updates by the end of this week hopefully!

[Vegard_]

Can't wait to see how this turns out!

[DJ46]

I absolutely love this.

 

For some reason it reminded me of a build I saw on here years ago, and today I finally found it - the H2O-Micro by QinX.

I'm mentioning it because you might find some useful info in that thread - I skimmed through it looking for a specific tubing size, but even if it isn't written somewhere you could try to estimate it based on the 80mm fans for example. It also shows of the cooling potential (though it is a different radiator setup) with power consumption and temps.

 

Here is a link to a specific post that shows off the assembled loop:

 

[Hiraeth]

10 hours ago, Vegard_ said:

Can't wait to see how this turns out!

Thanks! Will bring some updates soon!

10 hours ago, DJ46 said:

I absolutely love this.

 

For some reason it reminded me of a build I saw on here years ago, and today I finally found it - the H2O-Micro by QinX.

I'm mentioning it because you might find some useful info in that thread - I skimmed through it looking for a specific tubing size, but even if it isn't written somewhere you could try to estimate it based on the 80mm fans for example. It also shows of the cooling potential (though it is a different radiator setup) with power consumption and temps.

 

Here is a link to a specific post that shows off the assembled loop:

 

Thank you for your support!
I remember seeing that one when I researched some weeks ago. It also gives me more confidence that my 140mm rad will be alright. The 80x2 rad in The H2O micro has an active area covered by the fans at 7200 mm^2, the 140mm rad has an active area of 11600 mm^2. I hope for some great downvoltage possibilities on the 3070 and the 5900x when AMD get their new software out. Also see the use of smaller diameter tubing. Looks like pushin 8/6mm 

[DJ46]

15 minutes ago, Hiraeth said:

Thanks! Will bring some updates soon!

Thank you for your support!
I remember seeing that one when I researched some weeks ago. It also gives me more confidence that my 140mm rad will be alright. The 80x2 rad in The H2O micro has an active area covered by the fans at 7200 mm^2, the 140mm rad has an active area of 11600 mm^2. I hope for some great downvoltage possibilities on the 3070 and the 5900x when AMD get their new software out. Also see the use of smaller diameter tubing. Looks like pushin 8/6mm 

I recently finished a system with a 5600X that used the stock Wraith Stealth (for a stupid reason that I won't go into). I looked into undervolting it but the moment I set the CPU voltage from Auto to Offset it completely stopped boosting.

Looked into it and found out it is better to tune these CPUs by setting manual PBO limits. I set the power limit to 65W and the thermal limit to 80°C. (Curve Optimizer wasn't in the BIOS on that board.)

Under single core tasks it still hit 4.65 GHz like it did out of the box, with all core loads starting out at 4.2 and slowly dropping as the temperature rises.

It made me wonder how the chip could run with some proper cooling, but it might help you tame the 5900X.

[Hiraeth]

39 minutes ago, DJ46 said:

I recently finished a system with a 5600X that used the stock Wraith Stealth (for a stupid reason that I won't go into). I looked into undervolting it but the moment I set the CPU voltage from Auto to Offset it completely stopped boosting.

Looked into it and found out it is better to tune these CPUs by setting manual PBO limits. I set the power limit to 65W and the thermal limit to 80°C. (Curve Optimizer wasn't in the BIOS on that board.)

Under single core tasks it still hit 4.65 GHz like it did out of the box, with all core loads starting out at 4.2 and slowly dropping as the temperature rises.

It made me wonder how the chip could run with some proper cooling, but it might help you tame the 5900X.

Yeah, I've heard that 5000-series (and past series as well), are horrible at undervolting right now. AMD is realeasing new undervolting software in december/january from my understanding. I also read about what you said, that I could set it to 65W, it feels weird for a 105W TDP CPU though. I have not tried changing anything in BIOS, but I did try the AMD master software, and put the voltage at fixed 1.1375v, which brought it down to 95W from 115W. But that is "only" 20W, what I am more curious about is 3070 undervolting. I think it is at 220W max, and I hope to get it down to at least 160W with no or little performance loss. That would do wonders on the temperature.

[DJ46]

15 minutes ago, Hiraeth said:

Yeah, I've heard that 5000-series (and past series as well), are horrible at undervolting right now. AMD is realeasing new undervolting software in december/january from my understanding. I also read about what you said, that I could set it to 65W, it feels weird for a 105W TDP CPU though. I have not tried changing anything in BIOS, but I did try the AMD master software, and put the voltage at fixed 1.1375v, which brought it down to 95W from 115W. But that is "only" 20W, what I am more curious about is 3070 undervolting. I think it is at 220W max, and I hope to get it down to at least 160W with no or little performance loss. That would do wonders on the temperature.

Yeah, 65W would probably be too low for a 5900X, I used that as it's the stock TDP for the 5600X. I couldn't wait for new software as the system isn't mine and the owner isn't a big tinkerer. The main thing was the temperature limit, as it was reaching >83°C in a cold room with the fan on the Stealth running full tilt and I didn't want it to run too hot in the summer.

I wonder what clocks the 5900X would hit at something like 80-90W though. I am definitely interested in how low you can get the GPU power.

 

[Hiraeth]

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]

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!

[Hiraeth]

Hi! Tested positive for covid last week and has been incapable of getting anything done the past week. I have been able to pull the 3070 apart though for some waterblock designing!

First of all I tubed the PC with 8/6 mm tubing. I was not really surprised, but I could not fully believe it until I actually tested it. The 8/6mm tubing shows no decrease in thermal performance at all! The only thing I could notably see was an increase in fan speed of about 30 RPM but that is within margin of error. 

 

 

Next I pulled the 3070 apart. This PCB is amazing for SFF builds.

 

 

Next I measured every part individually to be able to model it in scale in CAD. That will help with block planning a lot. This also mean I can make simulations easily and check various parameters as flow, temperatures, restriction and pressure drops within the block. Below is my proposed water flow. I have marked in yellow the parts which Nvidia have pads on which I will assume needs cooling. As I have no fans blowing air on the card, I will probably put some pads on extra parts. If you have any input, please tell me! The block design is one of the most critical in this build. Especially if I want to try to aim for a SUB 4L.

 

Thanks for cheering me on! Next time I will show you some simulations and tests of the waterblock. 

[Stygian Zenith]

RIP man. I know how bad covid can really be but in the meantime stay strong! Anyways, that pc is tiny and great for sff.

[Hiraeth]

Block-design is kind of ready for production, I ran some simulations today to make sure I got no deadspots and a good flow. I will 3D-print a test-block later to make sure everything fit as it should. I went with a droplet low resistance high-flow design to cope with the low pressure of the Alphacool pump. This ensures a low pressure drop in the block while maintaining a large area  for heat transfer. Water temperature should rise about 7.5 degrees given the flow and heat output. On the simulation I estimated VRAM power at 30W, VRM at 20W and core at 200W. I'm not really sure about the VRM and VRAM real output, however as I've been able to push my power consumption down to 160W from 216W I have a lot of play. Under no circumstance should the heat output to the water be more than 160W. Brining the CPU down from 105W -> 80W also make sure that I will have a full output of around 240W, which would heat the water 15-30 degrees at most. 

 

 

Below are my benchmarks with peak power consumption at wall. With stock settings in blue and undervolted (but maintained performance) in orange. 
I'm really satisfied with bringing down the power consumption this much. Will really improve my thermals given the small radiator size. It also give me confidence on the 500W PSU from Silverstone. 

[Hiraeth]

I finally got the Silverstone Flex ATX 500W in the mail! Time for some testing!

This is a pretty small PSU!

 

 

Inside is crowded! I understand why they put those noisy 40mm fans there. Gotta push some air.

As you can see on the image below I have fitted a temperature sensor onto the heatsink. I have also fitted a sensor to the fan for exhaust air measurements.

 

 

After a few tests on different wattage levels it was time to swap to the Noctua fans.

I bought one 10mm and one 20mm as the one that comes with the PSU is 15mm. I also have space for two fans in the case so I figured why not.

 

 

Just swapping the fans would leave a 5mm gap, so I quickly 3D-printed a temporary shroud to not lose static pressure.

 

 

Measurements were taken from the front where the fan is, and from the side as the images show.

 

 

 

I do not have a dBA reader, so all measurements are relative to one another (RMS readings).

For now I have just measured the noctuas in idle (120W).

It would be intuitive to think that the best way to benchmark would be to try to match the temperatures in different load scenarios.

I did not do this though for a good reason. The fan-curve and noise of the original fan is insanely conservative. Probably because this is ment for a server rack where it makes sense to push the temperature down to a few degrees even if it doubles the noise. I figured this can't be necessary, more on this later.

 

Below is the results from my tests.

 

 

As you can see the orig. fan is insanely noisy with readings up to 52dB at full load even though the temperature is just shy of 50C

So I took to the internet and found a review of the PSU on Anandtech. (Credits for the images)

 

 

As you can see, the PSU Over temperature protection cut the power at an exhaust temperature of 70 degrees and a heatsink temperature of 90 degrees.

After the shutdown they restarted the computer with no issues. This makes me confident that I can at least push the exhaust temperature to 50 degrees and the heatsink to 65 degrees with no problem in longevity. Also note that the full load test of 440W never will be a reality IRL. With undervolted CPU and GPU I only pull 340W in worst case scenario.

 

Here is a video of the sound levels and spectrograms. First is original fan at different loads, and last is the Noctua fan.

 

Up next is to continue on the GPU-block and to figure out a good way to control the PSU fan speeds. 

[DJ46]

Woah. I didn't think I could get any more excited about this system even when I thought you were planning to use an external PSU.

Now I definitely can't wait to see how it turns out!

[SFFDesigns]

This is an insane project, I just got into SFF with the NR200 and this project looks just insane. I cannot wait to see the finished product!

[La Lemon]

I am planning to build my own 6L case, it will be 28cm x 18cm x 13cm I am going to use my school CNC machine and CAD software to make the whole thing. I will base the design on the digital storm spark. Since they won’t release it (thanos meme “fine I’ll do it myself”). Hopefully, sine I have permission from my DT teacher who is the head of DT I can use the CNC machine to make a custom gpu water block for the asus dual mini 3060 ti, it will be tiny which will allow me to cram even more stuff inside. I am hoping to have a 3060ti and a ryzen 9 or 7 depending on what I can afford.

[ccRicers]

Following this because it's.. well... smol. SFF builds just add another layer of ingenuity with squeezing parts in a small case. I miss water cooling though.