Liquid temp question

[Langley_Man]

So im curious.

 

 say u have a aio cooler and your liquid temps around 25-30c under load

 

and staying stable at that temp but cpu temp is around 85ish.

 

For arguments sake, say u have a single 140 rad aio.

 

Would buying a bigger aio say a 3x140 see a difference in cpu temp.

 

Or is that baby aio basically doing it's job?

 

At what liquid temp would u say it wouldn't change the temp?

 

[Mira Yurizaki]

If there's that much of a temperature difference between the liquid and the CPU, the water block isn't making good enough contact. Assuming everything is good, "stable" temperature is where the liquid and CPU are roughly the same.

[Daniel644]

i'm 27c on the water temp at like 40c on the CPU, haven't checked it during stress testing, but the water is always gonna be colder then the CPU itself, you don't have 100% efficiency in any system, the more water and surface area you have the better heat transfer you will get, but neither will or should ever be equal, Water stays much colder, infact any temp over like 60c on water is actually bad for the cooler, as for whether your cooler is to small that depends on your CPU and how much an overclock you have going

[Revan654]

58 minutes ago, LangleyNerd said:

So im curious.

 

 say u have a aio cooler and your liquid temps around 25-30c under load

 

and staying stable at that temp but cpu temp is around 85ish.

 

For arguments sake, say u have a single 140 rad aio.

 

Would buying a bigger aio say a 3x140 see a difference in cpu temp.

 

Or is that baby aio basically doing it's job?

 

At what liquid temp would u say it wouldn't change the temp?

 

 

There are allot of variables to take into account. The more cooling space you have the better the temperatures will be.

[pyrojoe34]

That means you don't have adequate heat transfer from the CPU to the block.

Most of the time the issue is a bad mount causing poor transfer from the IHS to the block, change the thermal paste and remount it as flush and evenly as possible. The difference you are seeing is almost certainly from this.

The other possible issue is bad transfer from the CPU to the IHS (Intel only) which has been an issue for heavy OCers and can be fixed by delidding, but this would not explain such a huge difference and is probably not your issue.

 

For reference my i7-6800k with an H110i GTX after 15+ min under load sits at 62C while the water temp sits at about 43C. Even without delidding you should be getting the CPU and water temp within 25C or so of each other after extended load. If you don't then you need to remount it better.

 

If you AIO liquid is sitting near room temp then getting a bigger one wouldn't change a thing since it's already keeping the liquid as cool as possible and a bigger rad wouldn't change that. A bigger rad would only help if the liquid temp is high and the rad can't dissipate the heat well enough to keep up with heat generated.

[For Science!]

along with what @pyrojoe34 said, another explanation is that you haven't run the stress test for long enough to equilibrate your AIO coolant temperature.

 

Water takes a long time to heat (and cool) and so you need to stress your system for a good half hour or so to let the coolant reach a final temperature 

[Langley_Man]

thanks for all the replies. 

 

Im building another system for the wife, same build as i already have

i7 8700K

msi z370 msi plus

16GB DDR4 

 

i have a spare NZXT i shoved on it against my own wishes and i just ran prime95

for 3 hours maxing temps were at about 87C for over two hours and liquid temp never went above 27C

ohh PS 5ghz overclock

 

Vary stable except for this odd discrepancy in temp from liquid to CPU. 

i ran out of thermal paste will grab some tomorrow and try again.. 

[pyrojoe34]

1 hour ago, LangleyNerd said:

thanks for all the replies. 

 

Im building another system for the wife, same build as i already have

i7 8700K

msi z370 msi plus

16GB DDR4 

 

i have a spare NZXT i shoved on it against my own wishes and i just ran prime95

for 3 hours maxing temps were at about 87C for over two hours and liquid temp never went above 27C

ohh PS 5ghz overclock

 

Vary stable except for this odd discrepancy in temp from liquid to CPU. 

i ran out of thermal paste will grab some tomorrow and try again.. 

Yea something is wrong, is the pump running? Usually the liquid temp sensor gets hot when a pump fails though... Maybe a bad sensor? Did you already try remounting it with fresh paste?

[Langley_Man]

did u read the last line of what u quoted ? lol

 

yes pumps running, very low temps at idle.. cpu sits at 25-27.. just odd under load liquid temps dont go up that much

 

 

[Mick Naughty]

`So why do you need the liquid temps to go up?

 

[MaratM]

how did you measure liquid temp?

[andrewmp6]

If the room your in is cold then you can run cooler,Are you getting your temps out of a program or motherboard off the cpu ?The basic of cooling a cpu water or air is can the cooler keep up with the tdp heat from the cpu.On a stock clock speed most aios will run cool if the room its in isn't hot.Now once you overclock you dump a lot of heat,Or the room its in is 90 degrees f then things are gonna get hot fast.

[Langley_Man]

Alright so I kinda figured it all out.

 

I removed the cooler and noticed that there was play in the backplate when u screw down the cooler. 

 

Pretty sure i read about a few instances of this. So I grabbed a few rubber grommets from an old hard drive bay tray that had rubber spacers.

I linused them together to fully tighten the cooler down. 

 

That being said.

 

A 3 hours of prime95 torture test at 5.0hgz

cpu temp 82 degrees

Liquid temp 37

 

I have come to the conclusion it's a prime candidate for delid.

 

I have checked the cooler and it's working as it should. 

 

Thermal compound spread on cpu and cooler are as they should.

 

Only thing left is to assume it's the shitty thermal paste on the die itself.