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

[Hiraeth]

I guess you are using a specific software for these simulations, can you share a little more about it?

I am! Right now I am using Creo 7 which have a simulation section which include thermal, structural and fluid dynamic simulations. I'm pretty sure Solidworks have similar simulation capabilities. I think Fusion 360 (which is free) have flow simulation, but not sure if it has fluid dynamic simulation. It is not that hard to set up either. As long as you have a CAD-model of what you want to simulate, you set the material of the components, you set boundary conditions, that is, values at the boundaries. Lastly you press simulate and depending on how much processing power you got, it should show a pretty fine sim

If I have time I will probably try to make an airflow simulation of the case overall even if it really makes no difference as I only have so much space to work with. But simulations are always good knowhow!

 

[aquelito]

Love those tiny watercooled build ; reminds me of Qinx H2O Micro for the amazing engineer skills of yours.

Can't wait to see the end of it

 

[Curiosity]

very cool, i look forward to the finished product!

This will be smaller than my stx build, ha!

 

[Hiraeth]

Love those tiny watercooled build ; reminds me of Qinx H2O Micro for the amazing engineer skills of yours.

Can't wait to see the end of it

Thank you!

Yeah that H2O Micro was absurdly small, would be cool if it were updated with recent hardware to see how good it perform against ordinary MOBO+DDRs and if a 3070 would be able to be fitted. I also looked into making it smaller and using a power-brick, but I figured I'd like to keep it in one box.

Took a look at your projects, really liked the Neutrino which in similar in size!

very cool, i look forward to the finished product!

This will be smaller than my stx build, ha!

Thanks! I really hope I will be able to pull this one off!


Regarding the progress of the build, I'm now fully immersed in finalizing the GPU-block design. When that is done I will 3D-print the block (will probably take 8 hours) and fit it to see if everything lines up. Hopefully I will get time to do it this weekend to give you some updates on that!
I also just received a text telling me my Silverstone Flex ATX PSU will be delivered today! Can't wait!

 

[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.

 

[BaK]

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.

On what device do you read the temps?

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

At first listening I thought you forgot to record the Noctua, then realized it is the silence we hear at the end!

 

[Hiraeth]

On what device do you read the temps?


At first listening I thought you forgot to record the Noctua, then realized it is the silence we hear at the end!

I had an old Aquaero 6 LT laying around in a box, so I hooked up all the fans and tempsensors to it! Really good to have when testing.
I was hoping to be able to fit it in the case so I can control the PSU fans with the PSU temps. But right now I can't seem to make it fit.


Haha yeah, it was such a difference!

 

[anothernoob]

As far as noise is concerned, the sound clip you posted had the stock fans sounding like they're taking off, only to have to Noctua fan sounding like you forgot to add a sound clip Noise aside, the Noctua seems to show promising signs of a performance increase.

Seeing that you ran the Noctua test at idle, will you be controlling the fan completely independent of the original PSU fan controller? (If so, I assume you'll be using the temperature sensor and the fan to control it)

 

[Hiraeth]

As far as noise is concerned, the sound clip you posted had the stock fans sounding like they're taking off, only to have to Noctua fan sounding like you forgot to add a sound clip Noise aside, the Noctua seems to show promising signs of a performance increase.

Seeing that you ran the Noctua test at idle, will you be controlling the fan completely independent of the original PSU fan controller? (If so, I assume you'll be using the temperature sensor and the fan to control it)

I have two possible routes to go, and I'm not sure which one it is gonna be. Easiest way would be to control fans through bios and CPU temp and set the curve super conservatively with maybe 70% at all times and up to 100% as CPU approaches 70C.

This poses two different problems, first of all the CPU temp is just an approximate of the PSU temp. In some scenarios the GPU could run on its own and the system power draw would be 260W. The second problem is that the fans then might run louder than they have to.

The first problem is solved by testing which fan level I need as a minimum to dissipate the waste heat at 260W. This might be, say 70%, and then set the minimum fan level to that.

The second problem can only be solved by having actual temperature measurements from the PSU. That would also solve the first problem and can be achieved by me finding some sort of temperature interface module which makes me able to set the fan speed with PSU temps. I would probably then set the fan speed so that the heatsink never goes above 80C, or exhaust temperature never above 60C.

That would make it virtually noiseless in idle, and probably pretty decent in load.

 

[Lakimakromedia]

I made design block for my zotac 1070mini over half year ago. The cost was around 150$ for manufacture - only bottom copper side. For me pretty expensive. Also gpu start be noisy (coils). So I sold out it.
PCB generally very similar to this 3070....
U think there will be enough air for this rad?

 

[deeree]

Did you consider using FSP Flex guru 500W? I'd say it's got much better fan speed management.