More fans cause higher CPU temps?

[ItsBACKHAND]

Ill start by saying i am incredibly new to PC building.

 

I recently bought 3 new corsair sp120 fans for my pc. Case is a lian li o11 dynamic. in the process of replacing all 9 fans but bestbuy only had 1 pack in stock. So I installed the 3 new fans on my AIO and unplugged the other 6 old fans to cable manage better. After that i booted the pc up with just the three corsair fans to make sure they worked properly. Checked the CPU temp and it idled around 50c. Booted up a game and the CPU temp went up to around 75-80c. Shut it down to plug the other 6 fans up and after that the CPU idle temp was at 85-90c. Thought maybe air flow was the problem and took all the panels off and no change. Grabbed a box fan pointed at the pc and no change. Shut the PC down and unplugged the 6 old fans and the CPU temps were back to ~50c at idle. Does this make sense to anyone.

[Bombastinator]

Higher temps with more fans can totally happen. The thing with air cooling is its fluid dynamics and fluid dynamics is brain crushingly complex. Used to be too complex for even the biggest super computers in the world. That’s why nasa made wind tunnels.  Also why they don’t use em much anymore.  Basically all there is if you don’t want to do a hi Rez computer model of your case with every part in it in the exact place it is right down to the zip ties is do testing.  Lots of testing.

[Demonic Donut]

How are you orienting your fans? Are you checking GPU temps as well? My GPU kicks out enough heat that changing fan orientation to prevent hot GPU exhaust from going to my CPU cooler lowered temps a few degrees.

[ItsBACKHAND]

32 minutes ago, Demonic Donut said:

How are you orienting your fans? Are you checking GPU temps as well? My GPU kicks out enough heat that changing fan orientation to prevent hot GPU exhaust from going to my CPU cooler lowered temps a few degrees.

I had 3 intake on bottom. 3 top mounted pushing air out and 3 with the AIO pushing out the back of the case. Which may not seem like enough intake and probably wasnt. i figured that the fan i had pointed at the open case would improve temps if that was the issue. I will say i have a new 360 mm aio on the way and that will change the mounting. probably top mounted aio with intakes on the bottom and sides. And yes GPU temps were fine.

[coreygibson]

CPU idle at 85-90c is way too high to be inefficient airflow. Try remounting your cooler.

 

also what are the specs of your system, particularly CPU. any overclocks?

[YoungBlade]

If the AIO is pushing air out of the case instead of pulling it in, it makes sense that a fan configuration change would change the temperature. The AIO is drawing air from the inside of the case, so the temperature inside the case will act as the ambient temp. Because your GPU looks to be an open-air shroud one, it puts off a lot of hot air into your case.

 

I'm not a physicist, nor engineer, and definitely not a fluid dynamicist, so this is all guesswork, but I've used my amazing* MS Paint skills to give you an example of what might be happening.

So when the fans are on, the two in the bottom right are basically just off in their own world. The bottom pulls in air and it gets vented back out immediately. The hot air from the graphics card mixes with the cooler air coming in from the bottom. That air is pushed up by the bottom fans and pulled up by the radiator fans. So now your AIO is getting most of its air pre-heated by the GPU.

When the fans are off, most of the GPU's heat is going to stay near the bottom, because there aren't as many fans trying to push it up. The easiest way out is through the holes in the rear PCIe covers. For the AIO, the easiest path for air is going to be through the holes in the back, which will allow for cooler, external air to enter.

 

This is probably not specifically what's happening, but it could be something like that.

 

*MS Paint skills may not actually be amazing

[ItsBACKHAND]

3 minutes ago, coreygibson said:

CPU idle at 85-90c is way too high to be inefficient airflow. Try remounting your cooler.

 

also what are the specs of your system, particularly CPU. any overclocks?

no overclocks. CPU is a ryzen 5 3600 and GPU is a 2060. 

[coreygibson]

12 minutes ago, YoungBlade said:

If the AIO is pushing air out of the case instead of pulling it in, it makes sense that a fan configuration change would change the temperature. The AIO is drawing air from the inside of the case, so the temperature inside the case will act as the ambient temp. Because your GPU looks to be an open-air shroud one, it puts off a lot of hot air into your case.

 

I'm not a physicist, nor engineer, and definitely not a fluid dynamicist, so this is all guesswork, but I've used my amazing* MS Paint skills to give you an example of what might be happening.

 

So when the fans are on, the two in the bottom right are basically just off in their own world. The bottom pulls in air and it gets vented back out immediately. The hot air from the graphics card mixes with the cooler air coming in from the bottom. That air is pushed up by the bottom fans and pulled up by the radiator fans. So now your AIO is getting most of its air pre-heated by the GPU.

 

When the fans are off, most of the GPU's heat is going to stay near the bottom, because there aren't as many fans trying to push it up. The easiest way out is through the holes in the rear PCIe covers. For the AIO, the easiest path for air is going to be through the holes in the back, which will allow for cooler, external air to enter.

 

This is probably not specifically what's happening, but it could be something like that.

 

*MS Paint skills may not actually be amazing

While i'd expect some change in temp. That wouldnt account for CPU idle at 85-90c. It's just way too extreme for that.

 

 

2 hours ago, ItsBACKHAND said:

Ill start by saying i am incredibly new to PC building.

 

I recently bought 3 new corsair sp120 fans for my pc. Case is a lian li o11 dynamic. in the process of replacing all 9 fans but bestbuy only had 1 pack in stock. So I installed the 3 new fans on my AIO and unplugged the other 6 old fans to cable manage better. After that i booted the pc up with just the three corsair fans to make sure they worked properly. Checked the CPU temp and it idled around 50c. Booted up a game and the CPU temp went up to around 75-80c. Shut it down to plug the other 6 fans up and after that the CPU idle temp was at 85-90c. Thought maybe air flow was the problem and took all the panels off and no change. Grabbed a box fan pointed at the pc and no change. Shut the PC down and unplugged the 6 old fans and the CPU temps were back to ~50c at idle. Does this make sense to anyone.

one thing that might be happening is when you plug in your other fans, either the fans connected to your rad shut off or your pump shuts off. also, if you added fans to your radiator for push/pull (i cant quite tell if you did), make sure they are not blowing different ways.

[ItsBACKHAND]

16 minutes ago, YoungBlade said:

If the AIO is pushing air out of the case instead of pulling it in, it makes sense that a fan configuration change would change the temperature. The AIO is drawing air from the inside of the case, so the temperature inside the case will act as the ambient temp. Because your GPU looks to be an open-air shroud one, it puts off a lot of hot air into your case.

 

I'm not a physicist, nor engineer, and definitely not a fluid dynamicist, so this is all guesswork, but I've used my amazing* MS Paint skills to give you an example of what might be happening.

So when the fans are on, the two in the bottom right are basically just off in their own world. The bottom pulls in air and it gets vented back out immediately. The hot air from the graphics card mixes with the cooler air coming in from the bottom. That air is pushed up by the bottom fans and pulled up by the radiator fans. So now your AIO is getting most of its air pre-heated by the GPU.

When the fans are off, most of the GPU's heat is going to stay near the bottom, because there aren't as many fans trying to push it up. The easiest way out is through the holes in the rear PCIe covers. For the AIO, the easiest path for air is going to be through the holes in the back, which will allow for cooler, external air to enter.

 

This is probably not specifically what's happening, but it could be something like that.

 

*MS Paint skills may not actually be amazing

I think you are correct. When my 360mm aio comes in im going to swap the orientation to be 3 bottom intake. 3 side intake and. 3 top exhaust with the AIO. may not work but either way looks like i got some experimenting to do.

[coreygibson]

2 minutes ago, ItsBACKHAND said:

I think you are correct. When my 360mm aio comes in im going to swap the orientation to be 3 bottom intake. 3 side intake and. 3 top exhaust. may not work but either way looks like i got some experimenting to do.

I dont think that is your problem, but I would go with that config as well

[Bombastinator]

41 minutes ago, coreygibson said:

While i'd expect some change in temp. That wouldnt account for CPU idle at 85-90c. It's just way too extreme for that.

 

 

one thing that might be happening is when you plug in your other fans, either the fans connected to your rad shut off or your pump shuts off. also, if you added fans to your radiator for push/pull (i cant quite tell if you did), make sure they are not blowing different ways.

Woah. 80c cpu idle?  That sounds like a mount problem.  Or maybe a pump issue.  With that kind of idle temp I’d be looking at maybe the pump cable being pulled out or something.

[ItsBACKHAND]

1 minute ago, Bombastinator said:

Woah. 80c cpu idle?  That sounds like a mount problem.  Or maybe a pump issue. 

i would agree except literally cutting the other 6 fans off fixed the idle and brought it back down to ~50c. however i did decide to replace the aio just to be on the safe side.

[Blue4130]

39 minutes ago, ItsBACKHAND said:

I think you are correct. When my 360mm aio comes in im going to swap the orientation to be 3 bottom intake. 3 side intake and. 3 top exhaust with the AIO. may not work but either way looks like i got some experimenting to do.

The fact that it doesn't change when you take the side panel off and use a box fan should tell you that it's not a case fan issue. 

 

Did you unmount the aio to change the fans? If you did, you didn't remount correctly. Pull it off, check that everything looks good and remount. Make sure that you are tightening the screws down in a cross pattern EVENLY and fully. 

[ItsBACKHAND]

1 minute ago, Blue4130 said:

The fact that it doesn't change when you take the side panel off and use a box fan should tell you that it's not a case fan issue. 

 

Did you unmount the aio to change the fans? If you did, you didn't remount correctly. Pull it off, check that everything looks good and remount. Make sure that you are tightening the screws down in a cross pattern EVENLY and fully. 

the aio hasnt been taken off since the 3 new fans were put on. booted up with just them and had no issue. booted up with all 9 fans had issue. booted up with just 3 fans again had no issue.

[Bombastinator]

11 minutes ago, ItsBACKHAND said:

i would agree except literally cutting the other 6 fans off fixed the idle and brought it back down to ~50c. however i did decide to replace the aio just to be on the safe side.

So a mount change.  I can see possibly static pressure from the AIO radiator fans turning into it not enough to get air pumping through the top radiator. 80c idle is high for even that though.

[Bombastinator]

6 minutes ago, ItsBACKHAND said:

the aio hasnt been taken off since the 3 new fans were put on. booted up with just them and had no issue. booted up with all 9 fans had issue. booted up with just 3 fans again had no issue.

Doesn’t mean the pump power cable couldn’t be knocked loose though.

[ItsBACKHAND]

Just now, Bombastinator said:

So a mount change.  I can see possibly static pressure from the AIO radiator fans turning into it enough to get air pumping through the top radiator. 80c idle is high for even that though.

sorry. i havent replaced it yet. ive only ordered one. itll be in monday

[Bombastinator]

1 minute ago, ItsBACKHAND said:

sorry. i havent replaced it yet. ive only ordered one. itll be in monday

Nono any time you take the cooler off the cpu it’s a mount change.  Are you cleaning and reposting the cpu and cooler block when you do that btw? That alone can be a problem.

[ItsBACKHAND]

6 minutes ago, Bombastinator said:

Nono any time you take the cooler off the cpu it’s a mount change.  Are you cleaning and reposting the cpu and cooler block when you do that btw? That alone can be a problem.

gotcha and if by reposting you mean cleaning and applying new thermal paste then yes i did do that when i originally installed the 3 new fans. also the pump was running each time if the pump fan in dragon center means that. keep in mind im new to this. is the Pump fan reading in dragon center the actual pump?

 

[Bombastinator]

12 minutes ago, ItsBACKHAND said:

gotcha and if by reposting you mean cleaning and applying new thermal paste then yes i did do that when i originally installed the 3 new fans. also the pump was running each time if the pump fan in dragon center means that. keep in mind im new to this. is the Pump fan reading in dragon center the actual pump?

 

Agh typo on my part. Reposting should have been repasting.  Ihateautocorrect.

 

 Not sure what you mean by the dragon center.  Could be the lighted logo on the AIO pump.  Most commonly the AIO pump is mounted on top of the cold plate in an AIO.  They can sometimes be in other places for patent avoidance reasons.  I didn’t know there was any sort of readout there on that one.  Whether it is lighted or not would say whether or not it is plugged in though.  One common indicator for moving water in an AIO is a little plastic paddle wheel that spins if the water is moving.  Sometimes systems have them, sometimes they don’t.

[ItsBACKHAND]

1 hour ago, Bombastinator said:

Agh typo on my part. Reposting should have been repasting.  Ihateautocorrect.

 

 Not sure what you mean by the dragon center.  Could be the lighted logo on the AIO pump.  Most commonly the AIO pump is mounted on top of the cold plate in an AIO.  They can sometimes be in other places for patent avoidance reasons.  I didn’t know there was any sort of readout there on that one.  Whether it is lighted or not would say whether or not it is plugged in though.  One common indicator for moving water in an AIO is a little plastic paddle wheel that spins if the water is moving.  Sometimes systems have them, sometimes they don’t.

Sorry dragon center is the software for my motherboard and on it his a readout for PUMP fan. Which is around 1500 rpm. And the light was always on but the aio has two cables on it. One on the cpu mount and one on the radiator itself. Its an ibuypower aio.

[Bombastinator]

30 minutes ago, ItsBACKHAND said:

Sorry dragon center is the software for my motherboard and on it his a readout for PUMP fan. Which is around 1500 rpm. And the light was always on but the aio has two cables on it. One on the cpu mount and one on the radiator itself. Its an ibuypower aio.

Ah. I’ve never owned an MSI motherboard so I don’t know their software.

[thrasher_565]

its probly the cpu only getting fresh air from the back fan and the hot air form the gpu as the side is exhaust starving the cpu cooler for air. im guessing gpu temps were fine?

[Blue4130]

15 minutes ago, thrasher_565 said:

its probly the cpu only getting fresh air from the back fan and the hot air form the gpu as the side is exhaust starving the cpu cooler for air. im guessing gpu temps were fine?

Don't you think he would have seen a change in temps when he took the side panel off and pointed a house fan at it? (he claims no change) We aren't getting the whole story somewhere...

[thrasher_565]

1 minute ago, Blue4130 said:

Don't you think he would have seen a change in temps when he took the side panel off and pointed a house fan at it? (he claims no change) We aren't getting the whole story somewhere...

hmm maybe the aio is plugged in to a different header or hub or something. dose sound weird thow