CPU temp 30c at idle, 90c at full load. Wtf?!

SlapDashAsh

SlapDashAsh

SlapDashAsh

Associate
Joined
18 Apr 2013
Posts
15
Hi,

I've recently built a new gaming PC using a Gigabyte GA-78LMT-USB3 motherboard, AMD FX-8320 cpu and Zalman CNPS8900 Quiet cooler.

I've been using Speedfan and HWmonitor to check CPU temps and something odd is happening. At idle it sits at a comfortable 30-35 degrees C, which I thought was a decent temp. But when I play a game it jumps to 90c.

I thought increasing the fan speed would help when it gets hot but the cooler only goes to 1500rpm max, which it's already hitting. And it's definitely throttling the speed as the temp rises, I opened the case and made sure of it.

Please help!
 
Hi,

Is the cooler mounted correctly and tightly to the board? is there a rice grain/pea sized blob of paste used?
 
Yeah. I used a pea sized blob and screwed it on pretty tight. Maybe I should start again, clean off all the paste and remount.

So, are my symptoms sounding like it's not installed correctly?
 
Possibly, but then I have just Google'd the cooler and the first review suggests it wasn't the best cooler in the world even when it was first released.

I wonder if its actually capable of cooling a FX CPU in the first place to a satisfactory level.
 
1500 RPM is too low, the fan is supposed to be rated up to 2800 RPM.

You should go into the BIOS and disable any CPU Qfan functions, then check if the fan is running at its maximum speed.

I'm not entirely confident that cooler is capable of cooling a 125W chip.
 
Apparently the CNPS8900 Extreme goes up to 2800 RPM, but the Quiet edition only does 1500 RPM.

I did the BIOS changes you suggested but it's still only hitting 1500 RPM :(

I've struggled to find a decent low-form cooler that'll fit in my case (Gigabyte GZ-MA02 4-in-1). The Hydro 212 didn't fit and neither did the Corsair H55. Do you guys have any other suggestions?

Also, worth noting is the stock fan that came with the CPU gave very similar temp readings (35c->90c), but was obviously louder.
 
You should alter the voltages in bios if you have not done so. Auto will tend to overvolt the CPU under load. try vcore of 1.35V to start with at stock speeds.

What case and fans are you using? EDIT as above.

With only one 80mm exhaust fan, it could be heating up the case very quickly. What GPU is installed?

With slots at the bottom, all the airflow is rising past the CPU to the exhaust fan. Not in itself an issue, but it needs to be exhausted quickly.
 
Last edited:
SlapDashAsh said:
Apparently the CNPS8900 Extreme goes up to 2800 RPM, but the Quiet edition only does 1500 RPM.

I did the BIOS changes you suggested but it's still only hitting 1500 RPM :(

I've struggled to find a decent low-form cooler that'll fit in my case (Gigabyte GZ-MA02 4-in-1). The Hydro 212 didn't fit and neither did the Corsair H55. Do you guys have any other suggestions?

Also, worth noting is the stock fan that came with the CPU gave very similar temp readings (35c->90c), but was obviously louder.
Click to expand...


Theres more too I've noticed.,

The case you say you have has just a single 8cm fan fitted.

Most modern cases use 12cm fans and usually one intake and one exhaust.


The motherboard you are using is also not ideal, there are no VRM heatsinks around the CPU socket keeping the power circuitry cool which will in turn possibly throttle the CPU quicker also a lack of power phases does not help.

There are no good MATX boards for FX CPU's, they are all 7 series chipset based and have a lack of power circuitry for these demanding FX CPU's.
 
JonSmith said:
I'm not entirely confident that cooler is capable of cooling a 125W chip.
Click to expand...

In reviews it cooled an overclocked 2500K so should be able to, I think the issue is obviously that it's only running at low PWM speed.

OP the setting you need to disable is "CPU Smart FAN Control" in the menu "PC Health Status", if you have done that and it's still only running at 1500RPM then either the cooler or motherboard is faulty. Try plugging it into the SYS fan header as I don't believe that can do speed control.

*EDIT*

SlapDashAsh said:
Apparently the CNPS8900 Extreme goes up to 2800 RPM, but the Quiet edition only does 1500 RPM.
Click to expand...

Yeah, that's not going to be enough.
 
Last edited:
Somewhere I saw documentation saying 90c was maximum for FX-8320, but I wouldn't go above 65c myself.

I agree with Jon, the CNPS8900 is probably not not enough cooler
Indeed
  • CNP8900 Quiet fan is only rated 1500rpm.
  • CNP8900 Extreme fan is rated 2800rpm.

What is your CPU clearance?
  • Motherboard to sidecover measurement will do.
  • GPU to center of CPU measurement too please.
  • Does the side vent line up with CPU?
  • What is your budget?

What GPU are you using?
What case fans are there?
 
I'll only be able to measure when I get home in a few hours.

So, do we think the cooler is installed correctly but just not powerful enough?
And would the 2800rpm do the trick?
 
Correct me if I'm wrong, but it's starting to look like I'll have to buy a new case to fit a new cooler (eg. a Hydro 212) :(

Obviously this is less than ideal and I'd like to spend as little as possible to rectify my problem. So I don't make any more mistakes what would you guys suggest for replacement parts given my current setup...

Recap:
Chip: AMD FX-8320
Board: Gigabyte GA-78LMT-USB3
Current case: Gigabyte GZ-MA02 4-in-1
Current cooler: Zalman CNPS8900 Quiet
 
Just give a budget and someone will spec you up a better Intel Rig, your cannot ideally 80mm cooling today, airflow and noise wise.

You have already learned a costly mistake above.

ATX at least size wise for gaming.
 
SlapDashAsh said:
I'll only be able to measure when I get home in a few hours.

So, do we think the cooler is installed correctly but just not powerful enough?
And would the 2800rpm do the trick?
Click to expand...
Can't say until I know more, like what space you have and how case cools. If you have time to read it, this is a basic case cooling guide:
http://forums.overclockers.co.uk/showpost.php?p=26159770&postcount=7

SlapDashAsh said:
Correct me if I'm wrong, but it's starting to look like I'll have to buy a new case to fit a new cooler (eg. a Hydro 212) :(

Obviously this is less than ideal and I'd like to spend as little as possible to rectify my problem. So I don't make any more mistakes what would you guys suggest for replacement parts given my current setup...

Recap:
Chip: AMD FX-8320
Board: Gigabyte GA-78LMT-USB3
Current case: Gigabyte GZ-MA02 4-in-1
Current cooler: Zalman CNPS8900 Quiet
Click to expand...

I've used a little AXP-100 on a i7 920 with no problems... and it's only 121x105x58mm.


AXP-100 w/ TY-100 pulling out
Tested with i7 920 stock
Handbrake @ realtime

Room ambient . Idle CPU; . . . . . rpm; Cooler Exhaust. 100% CPU; rpm; Cooler Exhaust . mobo; . NB; . Cooler intake*
21.5c . . . . . . . . 32-31-35-31c 2450rpm 26.0c . . 62-62-63-61c 2450rpm . . . 33.5c . . . 34c . . 46c
21.5c . . . . . . . . 33-31-35-31c 2250rpm 25.5c . . 63-64-65-63c 2250rpm . . . 34.5c . . . 37c . . 45c
21.5c . . . . . . . . 33-32-37-33c 2000rpm 30.0c . . 64-65-65-64c 2000rpm . . . 35.5c . . . 34c . . 48c
21.5c . . . . . . . . 35-34-39-34c 1750rpm 28.5c . . 66-67-66-65c 1750rpm . . . 37.5c . . . 35c . . 50c
21.5c . . . . . . . . 34-33-38-32c 1500rpm 27.0c . . 69-70-70-69c 1500rpm . . . 39.5c . . . 34c . . 51c
21.0c . . . . . . . . 35-34-38-33c 1200rpm 28.0c; 34c & 47c mobo & NB
*I neglected to put a probe under cooler, sorry.
.2450rpm is maximum rpm mounted pulling out

I re-ran a couple of the fan pushing in tests. Intake air is much warmer than room ambient.

AXP-100 w/ TY-100 pushing in
Tested with i7 920 stock
Handbrake @ realtime

Room ambient . Idle CPU; . . . . . rpm; Cooler Exhaust. . 100% CPU; rpm; Cooler Exhaust . mobo; . NB; . Cooler intake*
21.5c . . . . . . . . . 33-34-35-31c 2400rpm 28.0c . . 67-68-67-66c 2400rpm . . . 39.5c . . . 36c . . 51c
22.0c . . . . . . . . . 33-34-35-31c 2250rpm 28.0c . . 68-68-69-67c 2250rpm . . . 39.5c . . . 36c . . 51c . . 30.0c
22.5c . . . . . . . . . 36-35-39-33c 2000rpm 30.0c . . 69-70-70-69c 2000rpm . . . 40.0c . . . 39c . . 51c
22.5c . . . . . . . . . 35-34-38-33c 1750rpm 29.5c . . 72-73-73-71c 1750rpm . . . 43.0c . . . 40c . . 54c
22.5c . . . . . . . . ; 35-35-39-34c 1500rpm 30.0c . . 76-78-77-75c 1500rpm . . . 47.0c . . . 40c . . 57c
23.0c . . . . . . . . . 37-36-41-36c 1200rpm 31.0c; 39c & 46c mobo & NB
2400rpm is maximum rpm mounted pushing in
*Temperature of air 30mm above TY-100
 
jh30uk said:
Just give a budget and someone will spec you up a better Intel Rig, your cannot ideally 80mm cooling today, airflow and noise wise.

You have already learned a costly mistake above.

ATX at least size wise for gaming.
Click to expand...



You really do spout a load of rubbish sometimes.

There are plenty of people on here with overclocked Mini-ITX gaming rigs let alone the excellent M-ATX ROG boards. You do not need a ATX motherboard for gaming and overclocking.
 
Could be Jon. But it does have a rather low speed fan.. and being a down-flow could easily be heating up it's own cooling air. I've found reversing the cooler airflow often lowers them by 7-10c. Sadly don't think it can be done on this cooler.
 
Thanks for all the advice everyone, really appreciate it and please keep it coming.

Just because I like to live dangerously ;) what would happen is I threw caution to the wind and just let it run at 90c while playing games? They still run fine, but how much damage would I actually be doing?
 
SlapDashAsh said:
Thanks for all the advice everyone, really appreciate it and please keep it coming.

Just because I like to live dangerously ;) what would happen is I threw caution to the wind and just let it run at 90c while playing games? They still run fine, but how much damage would I actually be doing?
Click to expand...
Well you got the "live dangerously" part right. No idea how long it would last but it is hotter then recommended.. by 20-25c. :D

Do you have a good 120mm fan setting around? Unplug the cooler fan and set the 120 on top of fins first blowing in to see if it cools better... and then pulling air out to see if it cools even better.
Maybe slip some cotton buds sans cotton thru mounting holes to hold it in place?? Maybe a couple of rubber bands or zip-ties??
 
You must log in or register to reply here.
Back
Top Bottom