Water Temp - what's your max?

Chris Beard

Chris Beard

Chris Beard

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Hampshire
Hello Lovely forum,

I've recently set up my Aquasuite thingy with a hybrid temp sensor based on GPU/CPU and Water Temp.

In my experimentation I've found I can completely stop my fans (other than the PSU, next upgrade I guess) when idle and allow the radiators to run passive. The Water Temp seems to level off around 40c and I've set things up to start the fans around 43c.

How warm a water temp is everyone else comfortable with? I'm running food grade silicone tubing, so that should be good to well north of 100c; is there anything else to worry about?
 
Your tubing may be rated to 100 degrees but most other components are only rated to 60 degrees so be careful although to be honest if anybodys water temp hits 60 degrees then they would be better off with air cooling.

My water temp is usually between 19 and 22 degrees with the fans ( 8x Arctic Cooling P14) set to a almost silent 780rpm. In the summer I have seen the water temp hit just under 30 degrees but in Winter I often drop well into single figures. The joys of a windowsill mounted rad box with outside air going through it. One day I will invest in a Aquaero and disappear down the rabbit hole of endless sensors and other add-ons.
 
Ooft, I'd be sweating bullets at 40 degrees even if I know it's still within spec lol.

My idle profile is 600RPM on fans and 2000RPM on pump. Noctua fans so it's completely silent.

Water temp follows idle within 3 degrees, so water temp usually around 24-26 degrees. Under load pump goes up to around 4400RPM and fans scale to 1100RPM max. Water temp tends to be 29-31 degrees.

This is with 4 rads though so as usual rad space massively helps cooling.
 
Comfortable with up to 35ºC while gaming.
I flap if it hits 40 and turn it off when it reaches 45, although a big part of that will be because it's summer, it's baking hot anyway, and the PC is only dumping even more heat into the room.

I imagine the next two rounds of electricity price increases will see me chuck my PC in the bin anyway, though.
 
At idle/internet browsing etc I'm at +2-3 degrees over ambient with the fans at 800rpm. I have my fan curve linked to the water temp which keeps it maxing out at around 43 degrees at ~1000-1200rpm.
 
I have my fans on a 30% min - 80% max linear scale based on a water temp 30C min and 45C max. Hits about 37C max water temp atm but I expect it will go up a few degrees when ambient warms up a bit in the summer.
 
I have my fans set to similar as I W/C for consistent noise levels rather than max perf, my water settles at ~45C after a few hours of gaming, temps of components are all under their rated temps, I think the hottest things in my loop is GPU RAM at 68-70C and the CPU which hits similar ball park.

So long as it stabilizes and doesn't get into a thermal runaway scenario it is fine, ~700w of power has to go somewhere, this is doing it rather quietly whilst heating the room, its always summertime in my office when playing :D
 
I just did a load of stress testing overloading CPU and GPU to make sure even at max load it did not go too far, though I have not tested beyond 27C ambient and set my fans to slowly ramp on water temp they don't turn on until 30C and are on max at 45C but that is when I am gaming and have headphones on, even so it is not loud as they are low speed fans 1500rpm tops. When doing normal desktop stuff they are not spinning or perhaps doing 300rpm max.

I do have a second 14" touch screen I use to keep an eye on all temps and messages etc when playing and alarms setup if something goes out of whack, it never has done but so I'll always know :D
 
I have a 360mm and 240mm corsair xlr5's and pull around 300-350 watts from cpu and gpu while gaming at most. Water temps hit around 31.5c- 33.5c while gaming depending on the game i'm playing. This is with my fans set to run at 1500rpm max at 35c water temp. So it hovers around 1300rpm at 33.5c.
 
I considered doing what the OP is doing, but this being my first build I was not comfortable when the idle water temperature kept rising towards 40C. I realised that my plan for "fanless idle" was more "for the sake of it" than genuine need so I now have the fans on low during idle and I can't hear them and the water settles at about 33C. When I did my research I saw most advice refers to a delta with room temperature and a general expectation that maximum water temperature should be somewhere in the 30s range, so initially I set the fan & pump curves that allowed the water to reach about 38C in gaming. Whilst the fans were not really noisy I could hear them so I changed it so the maximum is about 40C. I have considered going higher but compared to my previous air-cooled PC this one is certainly not noisy so I'll keep it as it is.
 
Main rig hit 46 degrees when I was dumping 1.4kw or so (triple GPU and power hungry CPU) in summer on hot days when I was doing simulation modelling. More typically will top around low 30's to mid 30's for typical loads.

Gaming rig tops out low to mid 30's usually water temp wise and I expect high 30's in summer.

I would not like to go above mid 40's that often, have had plastic tubing fail at around that point before in a ITX build before, though admittedly I do use all metal tubes in builds anyways.
 
Chris Beard said:
Love the positive take :D

When deciding a constant fan speed how did you decide what that speed should be?
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I would advise against a constant fan speed if you have PWM fans, much better to properly tune them for watercooling. If by constant you meant putting the fans at one speed and leaving them at that all the time.

Aim for a water temp max under your heaviest load during realistic conditions (such as average ambient temp in the UK) and go from there. If the temps you set out for have noisy fans, then maybe decide to increase your water temp a bit if it's not quite high already. But in most cases you should still expect fan noise under 400~500w+ loads in an average case, with an average radiator setup. At the end of the day, watercooling is still technically air cooling ;) Spinning fans make noise, especially at 1000RPM+.

UK summers can get quite hot and as we don't tend to have air conditioning you do need to factor that in. But then again, winters can be stupidly cold. So a fan curve set in the winter might not be adequate in the summer lol.

Whereas if you set a fan curve based on water temp from around average room temp all year round, say 20~23 degrees, you'll probably find it's good all year round.

People tend to underestimate just how much impact fans have on watercooling, from the fan types themselves to any curve or speed used on the radiators. As they do how much extra rad space helps, but a lot of the time extra rads are just constrained by space in a case.

Intaking ambient air over your radiators is always best for temps, but I know in most case setups people have to consider some sort of exhaust over just relying on air finding its way out itself through ports/vents (which it does do surprisingly well).

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Most recent look at where my build has gotten to, all my rads are intake. I'm spoiled with 4 radiators, so that does allow quieter operation lol.

I do have to say as someone who changed from Arctic P12/QL120s, Noctua fans are a joy on the ears. At a minimum though, as pretty as they are, the QL120s are awful for watercooling quietly and at the lowest temps possible. Avoid! Other RGB fans do better.

If you've got a budget for it and want to spend on fans, screw paying the premium for something like the QL120s, honestly, bite your lip and buy non-RGB Noctuas (Or Silent Wings/any other good brand rad fans). You can still have some RGB, all my blocks are RGB and just recently I bought an RGB flow spinner to replace down the bottom on my next loop drain.
 
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Chris Beard said:
That sounds cool - is that off-the-shelf or something a bit more specialised?
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Quiet common now. Most the brands do it, Bitspower, Barrow and XSPC. Usually in few different colours. It fits into normal hardline fittings and does give a different look as you cannot see the fluid but I like it. Only caveat is outside of some prebent 90 degrees you can buy, you cannot shape it as its already plated chrome most the off shelf stuff. Hardcore modders do full custom metal in various metals, copper, brass and plate after for 0 fittings. Old pic of main rig kicking about to show how the metal looks. Some may not like the finish / fittings and can get pricey if using decent amount of fittings if you have angles, but like overall effect personall.

uC2kDKp.jpg
 
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