Strange Heat / CPU Fan Issues

[Brad-Pea]

Hi All,

Got a bit of a strange problem here..

When the computer is idle .. the CPU Temp sits at around 50 degrees c

When I load up a game (Saints Row 3 / Call of Duty etc)

The temperature rises, as I guess it should due to the more stress the computer is put under, but the CPU fan never speeds up to adjust to this new heat ... therefore the CPU will get to 60-70 degrees + and the CPU fan only spins at 2k RPM ... this obviously causes a problem whereby the machine is getting too hot as the CPU fan is not cooling it down...

Now what I have noticed is if I take the side / front of the case off .. the CPU fan will immediately speed up .. now this happens whether in game or computer just idle .. fan will spin up to around 5k RPM.

Now what is causing the fan to spin up when the front of the case is off? And spin back down when the front is back on?

Why is the CPU fan not spinning up when the case is all closed even though it is getting hotter?

Can bad thermal paste be the cause, should I remove and replace with new? Could it be a bad CPU cooler? But if it was that wouldn't it just not spin up at all ?

Hope someone can help.

Cheers.

 

[redduc900]

What CPU and HSF do you have? The board model might also help.

 

[Brad-Pea]

What CPU and HSF do you have? The board model might also help.

It's an AMD Phenom 9950 .. With stock HSF....

Motherboard is a : Gigabyte GA-MA790FX-DQ6

Cheers.

 

[Brad-Pea]

Any thoughts?

 

[Bobnova]

Try turning on the motherboard's fan control bits.

Most (all?) AMD fans of that era have an air temp sensor that controls fan speed. The idea being that if the incoming air is hotter the fan turns faster to compensate.
It sounds to me like the thermal paste isn't doing an especially good job, causing the CPU to run hotter at a given fan speed / air temp. With the case side off the airflow is very different, potentially letting that sensor heat up and crank the fan up. When the motherboard is feeding the fan a PWM signal that usually overrides the temp sensor.
Alternatively there may be a wire being bumped.

Another plan would be to get some new thermal paste and replace the stuff that's on there right now, in case it's gone downhill.

Yet another plan would be to spend $100 or so on a used PhII 955 (example, not my listing, I don't know the guy, your mileage may vary, etc. etc.) and get higher performance and cooler temperatures.

 

[Brad-Pea]

Try turning on the motherboard's fan control bits.

Most (all?) AMD fans of that era have an air temp sensor that controls fan speed. The idea being that if the incoming air is hotter the fan turns faster to compensate.
It sounds to me like the thermal paste isn't doing an especially good job, causing the CPU to run hotter at a given fan speed / air temp. With the case side off the airflow is very different, potentially letting that sensor heat up and crank the fan up. When the motherboard is feeding the fan a PWM signal that usually overrides the temp sensor.
Alternatively there may be a wire being bumped.

Another plan would be to get some new thermal paste and replace the stuff that's on there right now, in case it's gone downhill.

Yet another plan would be to spend $100 or so on a used PhII 955 (example, not my listing, I don't know the guy, your mileage may vary, etc. etc.) and get higher performance and cooler temperatures.

Thanks for the reply.

I guess the settings to change the fan control will be in the BIOS? Rather than running a programe ?

I'm thinking it may be bad thermal paste too ... Ill try to enable the settings and if no joy replace the paste ...

Thanks for the link on the processor, is that the same socket as my current processor so it would fit straight in ? I think if I were to spend $100 I'd hold of a while and upgrade the whole system ... CPU, Mobo and Ram. Besides my current spec seems run games no problem (Apart from the heat !)

Cheers.

 

[Bobnova]

It should fit, your motherboard BIOS needs to support it (it should, but it may need an update).
Other than that it'll use the same socket/RAM/etc.

 

[Brad-Pea]

Ok so I had a look around the BIOS..

I found a setting of .. CPU Smart FAN Control which was enabled..

And CPU Smart FAN Mode ... which was set to AUTO .. this could be changes to voltage or PWM .. would Auto suffice ?

So it looks like it was meant to do its job ?

I did notice that it the BIOS was on firmware F7B .. which according to this site : http://www.gigabyte.com/products/product-page.aspx?pid=2690#bios

Doesn't even exist ?

I have just updated to F7G which is the newest so will see if this resolves my problem .. Not sure where the F7B firmware came from ..

Cheers.

 

[Bobnova]

Try setting it to PWM.
Try turning off smart fan control too.
Essentially, try all the settings and see if any of 'em fix it for you

 

[Mr.Scott]

I have just updated to F7G which is the newest so will see if this resolves my problem .. Not sure where the F7B firmware came from ..

F7B was an earlier beta bios. As the beta's evolve, they delete the earlier one's in favor of the newer one's.

 

[Brad-Pea]

I see a new setting within pc health status on the bios ... That is : Hardware Thermal Control .. Enable/Disable .. What this does is : To reduce the CPU voltage and ration when the CPU temperature is too high ... This was enabled by default after the bios update and seemed to fix my problem. When I disabled it the problem came back. Will enabling this impact performance ?

I will change to PWM now and try.

Thanks Mr.Scott .. That clears that one up !

Cheers.

 

[Bobnova]

Test it and see what happens, that's the only way to know for sure.

 

[Brad-Pea]

Ok so changed to PWM did not change anything.

I then went and disabled smart fan control altogether ... which should put the CPU fan at full speed ... rebooted and went back into BIOS and it was reading the CPU fan at around 3229RPM ... surely that isn't full speed ? Not sure whats going on, whatever I try to do I cant get the fan spinning faster than 3K RPM ...

If the thermal paste was at fault I understand it would make the CPU etc hotter .... but wouldn't the fan still kick in at a faster speed ? Will check out replacing it anyhow..

Enabling the Hardware Thermal Control seems to be a fix, but not sure if its a good one .. When putting the machine under load (Prime 95) it will get to around 65 degrees c .. then the voltage of the CPU will drop to around 1.072 for a few seconds .. then back to 1.320 ... and carries on doing this ... the temp then doesn't get any higher.

Those values are rough i'm not at my machine to clarify.

Cheers.

 

[Mr.Scott]

Hardware Thermal Control .. Enable/Disable .. = Thermal throttle for the CPU. It keeps you from cooking your processor if the temp gets out of control. It's doing it's job, but that's not solving your problem.

Link to your cooler and fan please. I highly doubt 5k is possible on your fan. 3k is more realistic. In any case, your processor is not being cooled properly. First step would be to blow out the HS and replace the TIM.

 

[Johan45]

@ Mr. Scott I think he said stock H/S

One thing to consider is the 9950 (agena) is a 140 W super hot CPU.
I have a 9850 and with the stock H/S I was idling around 45°c and even at stock P95 would send it into the 70's almost instantly.
I also found it difficult to find consistent monitoring softwar. That could be my board though.

 

[Brad-Pea]

Yeh its just the stock H/S ... As per what came with the AMD Phenom 9950 ...

Regarding the speeds the more and more I try to make the fan speed up ... i'm doubting if I actually saw it hit 5K ... I'm 99% sure I did though !

Will give the machine a clean up tonight and replace the TIM and see what comes of it.

Yeh P95 sends it to 70 within 10-20 seconds if the hardware thermal control is disabled.

Cheers.

 

[Mr.Scott]

Agreed. I have a few Agena cores also. Super hot.
CoreTemp is about the best you can do for AMD.
I'd still clean it out and re-TIM it. It couldn't hurt.

 

[Johan45]

I tried a stock cooler from a PII965 and from my 8350. The only thing I found that even somewhat tamed it was a CM hyper 212 if that would fit in your case. They're only $30

 

[Brad-Pea]

Good news !

Cleaned out the machine of all dust etc ... It was quite dusty !

Cleaned and re applied new thermal paste ... all back together and now idle the machine sits around 30 degrees c !

And when put under load ... Prime 95 running for 5+ minutes it sits around 54 degrees c ....

Therefore i'd say the thermal paste was bad ? Or the amount of dust was blocking the air from the fan into the heatsink block?

After 10 mins of P95 running it only peeked at 55 degrees.

Thanks Johan about the CM Hyper 212 ... I will keep that in mind incase I need it further cooled .. that looks like a beast !

Cheers.

 

[Mr.Scott]

Nice!