Custom loop temperature measurement

[mickeej]

Hello can anyone tell me if its better to measure the water temperature or the cpu core temperature? Started from scratch last Christmas and designed and built my own wood  itx case and sprayed it white ! Decided to start again and transfer to an oak frame, while adding a second rad unfortunately the lcd i fitted last year as a sensor panel has stopped working so looking at either a new panel at 3x the cost or an old style digi water temperature sensor! Which measurement is more important?

[BobVonBob]

Water temperature is neat to know but totally irrelevant. The only thing that matters in the operation of the computer is how hot the components are.

[mickeej]

thanks will source a new panel and stick with cams as a display

[bowrilla]

Water/coolant temperature. The coolant temperature directly affects heat transfer from the blocks to the coolant and from the coolant to ambient air. Or to be more precise: the temperature difference.

 

And if your water runs very hot, you will risk damaging components up to the point of catastrophic failure. Granted, that is an extreme scenario that should not happen with standard components and a reasonable amount of radiator surface.

 

Also, coolant temperature is the only thing you can directly influence. Ramping up your fans will not have direct impact on CPU temps. What's actually happening is: you increase the airvolume going through the radiator which in turn means you reduce your coolant temps due to larger heat energy transfer. Since this is a slow process though (it takes 1.16Wh of energy to increase the temperature of 1kg of water by 1K) the impact on your components is also very slow. Because of all this: it doesn't make much sense to regulate your loop by component temps.

[thrasher_565]

lets just say its complicated. to get to the exstream you one dont care how much its cost. that out out of the way. 

 

faster water flow rate the lower the temps.

faster fan or more static pressure fans deepening on rad thickness push pull of cores

seem like flow rate is better then a long slow flow so im guessing cross flow rads are better in this case but have not see any test on it.

run the loop in parallel 

duel pumps to increase flow rate

same id thow the hole loop no bottle necking

no 90degree angels use 2x 45 or hard tube is fine

de lid the cpu if posable and use liquid metal

more rad surface vs better fans will always win

and open air test bench will be atless 10 degrees cooler then the best air flow case.

 

that's about the best you can do on the stranded wc. if you want lower you need other methods

 

Edited November 16, 2021 by thrasher_565

[bowrilla]

Not entirely sure how this relates to the initial post but, a few comments on those statements.

4 hours ago, thrasher_565 said:

faster water flow rate the lower the temps.

 

Well, within reason yes but negligible. Your loop performance won't differ much whether you have 1/4GPM or 1GPM. The difference is maybe 2-3K difference in water temps and that also depends on where in the loop your measure. Yes, that will have some effect on heat transfer but this is not a one-way street since you'd be decreasing the delta between blocks and coolant but you'll be increasing the delta between coolant and ambient. Since the latter is usually smaller, slightly higher coolant temps might actually be beneficial overall.

4 hours ago, thrasher_565 said:

faster fan or more static pressure fans deepening on rad thickness push pull of cores

That's a very complicated topic since not all radiators have the same fin density but assuming the same fin density, then as a rule of thumb: the thicker the radiator the higher the restrictiveness for the air volume. That will then in turn require more static pressure, which then will require higher fan speeds and/or more fans which then in turn will lead to higher noise levels. 

 

Generally speaking: thicker radiators perform best at higher fan speeds and have their advantage in this region, at lower fan speeds they're at best equally in performance to slimmer radiators and sometimes even worse.

4 hours ago, thrasher_565 said:

seem like flow rate is better then a long slow flow so im guessing cross flow rads are better in this case but have not see any test on it.

Whether cross-flow rads have less restriction compared to regular "u-flow" rads highly depends on the specific model. To my knowledge, there are some radiators that have higher restrictiveness with the x-flow models.

 

4 hours ago, thrasher_565 said:

run the loop in parallel

That goes entirely against your suggestion of "more flow = better". I don't really agree with the initial expression in the first place but even assuming that it is true, splitting up flow into parallel runs will split flow. With a Y-splitter and two runs of the same restrictiveness, you will split flow 50:50. It works basically the same (in principle) as a current divider in electrical engineering.

 

4 hours ago, thrasher_565 said:

duel pumps to increase flow rate

No. Running pumps in series will (to my knowledge at least) increase head pressure (simple addition) but not flow. Increasing head pressure will actually lower flow. If you want to increase flow with dual pumps, you will have to run your pumps in parallel and then joing both runs with a Y-splitter.

 

4 hours ago, thrasher_565 said:

no 90degree angels use 2x 45 or hard tube is fine

Well, yes, that has an effect but depending on the fitting this is again negligible unless you make use of a ton of 90° fittings. Every single bend will increase restriction since it will disturb flow and make it turbulent. While you'll want turbulent flow in your blocks and radiators, you'll want laminar flow in your tubing. Every single bend will disturb this assuming a reasonably tight radius. In this regard, soft tubing is actually preferable since you'd have larger bend radii. You'll be using more angled adaptor fittings with hard tubing.

 

4 hours ago, thrasher_565 said:

de lid the cpu if posable and use liquid metal

Delidding is a very risky advice these days since most CPUs have soldered IHS. Yes, if you can do it, you might reduce temps noticeably. But then why adding the IHS again if you want maximum cooling performance? If you really want to get the maximum, then direct die mounting is the way to go. I wouldn't do it to my main rig but if you really want to push the limit: direct die.

 

4 hours ago, thrasher_565 said:

more rad surface vs better fans will always win

Well, more rad surface with crappy airflow fans won't do you any good. You'll need a good combination. You don't need to go for Noctua in order to get good radiator fans with high static pressure, Arctic has good 120mm and 140mm static pressure fans for a laughably low price tag. Good fans on your existing radiators is always better than just adding more radiators while continuing to use crappy fans.

 

5 hours ago, thrasher_565 said:

and open air test bench will be atless 10 degrees cooler then the best air flow case.

That's a bold statement and the actual performance depends heavily on the specifics of your system and case.

 

P.S.: please use punctuation and less hard line breaks. It makes your posts hard to read on smaller devices.

[thrasher_565]

7 hours ago, bowrilla said:

Not entirely sure how this relates to the initial post but, a few comments on those statements.

 

Well, within reason yes but negligible. Your loop performance won't differ much whether you have 1/4GPM or 1GPM. The difference is maybe 2-3K difference in water temps and that also depends on where in the loop your measure. Yes, that will have some effect on heat transfer but this is not a one-way street since you'd be decreasing the delta between blocks and coolant but you'll be increasing the delta between coolant and ambient. Since the latter is usually smaller, slightly higher coolant temps might actually be beneficial overall.

That's a very complicated topic since not all radiators have the same fin density but assuming the same fin density, then as a rule of thumb: the thicker the radiator the higher the restrictiveness for the air volume. That will then in turn require more static pressure, which then will require higher fan speeds and/or more fans which then in turn will lead to higher noise levels. 

 

Generally speaking: thicker radiators perform best at higher fan speeds and have their advantage in this region, at lower fan speeds they're at best equally in performance to slimmer radiators and sometimes even worse.

Whether cross-flow rads have less restriction compared to regular "u-flow" rads highly depends on the specific model. To my knowledge, there are some radiators that have higher restrictiveness with the x-flow models.

 

That goes entirely against your suggestion of "more flow = better". I don't really agree with the initial expression in the first place but even assuming that it is true, splitting up flow into parallel runs will split flow. With a Y-splitter and two runs of the same restrictiveness, you will split flow 50:50. It works basically the same (in principle) as a current divider in electrical engineering.

 

No. Running pumps in series will (to my knowledge at least) increase head pressure (simple addition) but not flow. Increasing head pressure will actually lower flow. If you want to increase flow with dual pumps, you will have to run your pumps in parallel and then joing both runs with a Y-splitter.

 

Well, yes, that has an effect but depending on the fitting this is again negligible unless you make use of a ton of 90° fittings. Every single bend will increase restriction since it will disturb flow and make it turbulent. While you'll want turbulent flow in your blocks and radiators, you'll want laminar flow in your tubing. Every single bend will disturb this assuming a reasonably tight radius. In this regard, soft tubing is actually preferable since you'd have larger bend radii. You'll be using more angled adaptor fittings with hard tubing.

 

Delidding is a very risky advice these days since most CPUs have soldered IHS. Yes, if you can do it, you might reduce temps noticeably. But then why adding the IHS again if you want maximum cooling performance? If you really want to get the maximum, then direct die mounting is the way to go. I wouldn't do it to my main rig but if you really want to push the limit: direct die.

 

Well, more rad surface with crappy airflow fans won't do you any good. You'll need a good combination. You don't need to go for Noctua in order to get good radiator fans with high static pressure, Arctic has good 120mm and 140mm static pressure fans for a laughably low price tag. Good fans on your existing radiators is always better than just adding more radiators while continuing to use crappy fans.

 

That's a bold statement and the actual performance depends heavily on the specifics of your system and case.

 

P.S.: please use punctuation and less hard line breaks. It makes your posts hard to read on smaller devices.

http://www.xtremesystems.org/forums/showthread.php?239246-How-to-Bend-Form-Tubing-for-Your-Setups

 

http://www.overclock.net/content/type/61/id/2468825/

 

 

ya i dont no how one gets more flow rate with more pumps but i no its posable.

 

ya an water block for an delided cpu would be better if you can get one that is.

 

its .5 lpm loss per 90 degree fitting.

Edited November 16, 2021 by thrasher_565

[bowrilla]

53 minutes ago, thrasher_565 said:

[...]

 

 

ya i dont no how one gets more flow rate with more pumps but i no its posable.

 

ya an water block for an delided cpu would be better if you can get one that is.

 

its .5 lpm loss per 90 degree fitting.

I think you've misunderstood me. I did not say that flow has no impact at all, I'm just saying that flow has less of an impact as people make of it as long as you stay in a reasonable range. Going down to 30l/h (~1.3GPM) is very much unreasonable and is probably lower than most pumps would ever go. Even an SPC pump running at 25% with 2 radiators and 2 blocks makes ~50l/h (I've tested that).

 

What I am saying is that 2 or 3K difference in water temperature does not make any significant difference unless you're hunting for max OC during torture testing.

 

der8auer's results are flawed since his flowrate is not matching his pump/loop configuration. How do I know? I've made a similar test myself running an SPC pump and the aforementionend loop configuration.

 

Funny enough: the first link you've provided basically says exactly the same as I do. Don't sweat so much about flow. Even at 60l/h (~1/4GPM) the increase was just 2-3K and before that the temps were basically stable. I want to point out though that him using absolute core temps instead of ΔT over ambient is not very reliable and it will introduce a potentially significant error.

 

Regarding thicker or slimmer radiators, I have distilled down some test results into a graph and that graph pretty much shows: at low revs there's no noticeable advantage of a thicker rad, potentially even a disadvantage. Once you increase your fan speeds, the curves tend to get closer until the thicker rads can play out their additional surface. HOWEVER, the difference is still within ~2K ΔT - which again is negligible in real world applications unless (again) you're hunting for max OC during torture tests.

 

And I've told you how you'd get more flow from more pumps: parallel pumps is the solution and not serial.

 

So what's your point with all the video links? 

[airborne spoon]

i have a temp probe that has G1/4 fitting and threads into my res. Since EK res has like a million unused ports on it i got it threaded into one right next to the out line going into the pump so i know what temp my water is as it enters the loop. I didn't buy it and i never would but i came across one in a scrap pile and its kinda cool so i keep it.

 

For CPU core temps that is too easy to look on MSI afterburner or pretty much any monitoring software.

[thrasher_565]

5 hours ago, bowrilla said:

I think you've misunderstood me. I did not say that flow has no impact at all, I'm just saying that flow has less of an impact as people make of it as long as you stay in a reasonable range. Going down to 30l/h (~1.3GPM) is very much unreasonable and is probably lower than most pumps would ever go. Even an SPC pump running at 25% with 2 radiators and 2 blocks makes ~50l/h (I've tested that).

 

What I am saying is that 2 or 3K difference in water temperature does not make any significant difference unless you're hunting for max OC during torture testing.

 

der8auer's results are flawed since his flowrate is not matching his pump/loop configuration. How do I know? I've made a similar test myself running an SPC pump and the aforementionend loop configuration.

 

Funny enough: the first link you've provided basically says exactly the same as I do. Don't sweat so much about flow. Even at 60l/h (~1/4GPM) the increase was just 2-3K and before that the temps were basically stable. I want to point out though that him using absolute core temps instead of ΔT over ambient is not very reliable and it will introduce a potentially significant error.

 

Regarding thicker or slimmer radiators, I have distilled down some test results into a graph and that graph pretty much shows: at low revs there's no noticeable advantage of a thicker rad, potentially even a disadvantage. Once you increase your fan speeds, the curves tend to get closer until the thicker rads can play out their additional surface. HOWEVER, the difference is still within ~2K ΔT - which again is negligible in real world applications unless (again) you're hunting for max OC during torture tests.

 

And I've told you how you'd get more flow from more pumps: parallel pumps is the solution and not serial.

 

So what's your point with all the video links? 

well we are talking max preforamce with out a care about how much it cost. so if there even a little bit it still is more preformace. well most people oc for a leader board and test with a torture test.

 

in the end all the talk of thicker rads and hi static pressure fans came to the concoction yes there's more prefromace but not worth the cost. that was the test $4 fan vs a $20 fan. hence why 30mm rad is the stander. but of cores if your space limited then you have to go thicker. but at that time there were wc case that had room for lots or rads so the cost of a thicker rad vs more rads made scene.

 

most times you might not notice any benefit of a oc. and you dont need 300 fps in a game that only needs 60 fps its just fun to have more... of cores a smooth frame rate is better then a hi frame rate any day.

 

 

[alphatessi]

Going back to the initial question. Temp sensors.

I use an aquacomputer octo with four temp headers.

2 for watertemps (before and after Radiators for the delta) and the radiatorfans are controlled according to the watertemp.

That way i can make sure, that the watertemp does not exceed a certain value.

Hooking the fans up to one hardwarepiece (especially with two or more heatsources) is problematic because it moves much more than the watertemp.

The other two tempheaders are for ambienttemp and casetemp to control the casefans.