Originally Posted by ruffhi
Barefoot ... how many pumps do you have driving your loop, how many radiators and coolers in that loop? What is your flow rate?
Hey ruffhi, I did do some flow testing of the loop after it was completely finished, and I of course took notes, but after your question I realized that that information never made it into any of the build log posts. So here it is now:
Devastator Flow Rate Testing
The system is one big loop with two Aquacomputer D5 PWM pumps in series. There are six radiators in total, four Hardware Labs Black Ice SR2 560mm in the top and bottom, and two Hardware Labs Black Ice SR2 280mm in front. Even though there are six radiators, these are low restriction radiators.
There are also seven water blocks, but they are all low restriction waterblocks, with the two video card waterblocks in parallel and the two hard disk drive waterblocks also in parallel.
I tested the pumps with various speeds between 40% and 100% to test the flow rates and what it did to loop temperatures. There were two specific speeds where the pumps would make a slight hum noise. At 70% pump speed there was a slight hum, and an even louder hum at 50% power. The rest of the speeds you really could not hear the pumps, and certainly would never hear them over the fan noise.
In this testing I was loading the system with the Real Bench stress test. This really puts just about the max load on the system that you can. This was done with an ambient temperature of 73° F, with the fans all set to 700 RPM and my 4.8 GHz daily overclock profile on the CPU with a 1.25 vcore.
Starting at 40% and going up 10% at a time all the way to 100% and then one final test back at 40% again. It is interesting how the air/water deltas are slightly better with 40% power and less flow rate.
This testing was done April 14, 2019 and shortly after this the maximum flow rate at 100% pump speed settled in at 1.1 GPM which is the same flow rate I’m getting as I write this, and I just now rechecked the flow rate at 40% power and it is .8 GPM.
I could run the pumps at a lower speed just fine, but since they are no louder running at 100% and the loop temperatures really did not vary too much with the pumps set to lower speeds, I would prefer to have a higher flow rate so I just leave the pumps set at 100% all the time.
As to the air/water deltas, the temperatures you see in the chart above are the hottest I’ve ever seen. I did get slightly better air/water deltas when the build was still in my work shop due to better air flow all around the case.
Now that it is in my office under the desk the air/water delta once the system is fully warmed up is usually around 3°C. It will go up a little bit more when gaming, but even this last summer when my office was almost 90°F the highest I ever saw the air/water delta get to was 4.5°C