# CPU fan speeds up



## music man (Dec 13, 2012)

My CPU fan gets extremely fast about every 20 minutes, and it lasts about thirty seconds.

I'm worried my computer is overheating. I use it for work. 

I had my motherboard replaced about a year ago. My CPU fan and my motherboard are now two different brands, so maybe the repair guys used the old fan with the new motherboard, somehow leading to this problem. 

I took the fan out and cleaned out a huge buildup of dust. Now the fan still speeds up every 20 minutes, but now it goes much faster. 

SPECS

Motherboardegatron. Model # M2N78-LA Violet.
CPU fan:Foxconn DC Brushless fan.
Processor:AMD Phenom II X4 820 processor 2.80ghz
Ram:8 gigs
Hard disk space: 920 gigs, 108 gigs free. 
Windows 7, service pack 1
Manufacturer:HP
Model:6404y
System type:64 bit operating system


----------



## WereBo (Apr 5, 2008)

Hi music man :wave:

It could be some program running in the background that does something intensive, every 20 minutes or so, or possibly when you had the motherboard replaced, the techs ran the cables slightly different and is now disrupting the airflow.

For a quick test, carefully place your fingertip on the CPU heatsink-vanes, they should be warm to very warm, if it makes you yell 'OUCH!' it's too hot.

For a precise test, download and install a wonderful freebie called 'PC Wizard' from here (*Link*) - When it's running, click on the 'Dial-face' icon to show your temperatures, you can get an idea of the temps under load by running something like a virus-scan in the background, whilst looking at the Wizard.

Meanwhile, check there's no cables close to the ends of the heatsink-vanes (alongside the length of the vanes is OK, but not blocking the gaps at the ends), also the vanes should be oriented 'front-to-back' (meaning as the air flows from the front of the PC to the rear) and post back with the various temps.

If you can take a photo of the PC's insides, that could help too :wink:


----------



## Tyree (May 10, 2009)

The CPU fan increases in speed when the CPU temp rises.
Is the CPU fan/heatsink free from dust buildup?
Has any hardware been upgraded/added to the original configuration?


----------



## The_Janitor (Sep 10, 2012)

If this is new, the Heat Sink could be clogged/dirty, and/or the thermal compound needs to be reapplied.

Also if this is new, I'd want to know what is causing the CPU to spike. Could be normal and something useful, could be something stupid, like an "updater" that doesn't need to run, or it could be dangerous, as in malware.


----------



## music man (Dec 13, 2012)

Ok, I downloaded "Open Hardware Monitor" to check my temperatures, but I don't really know how to interpret the data. I've attached that data, as well as a photo of the inside of my computer. 

Also, I should note that the fan hasn't acted up yet today, even though it has been for the past week or two. It's colder in my apartment, so maybe that's it. 

Thanks.


----------



## The_Janitor (Sep 10, 2012)

The fan looks dirty, even in a low-res photo. Probably should reapply thermal compound as well. That's a stock CPU fan & heat sink, and I'd recommend getting a better, aftermarket fan.

I know GPU's run hot, but yours seems way too hot. Also, it seems you are using way too much memory (more than 60%) for what looks like near-idle CPU speeds. That looks weird. Are you running something like "folding at home", or some other major number-crunching software? Video editing software? Playing a video in the background while you took this test? Why is GPU so hot, and why is the computer using so much memory?

And yet, as I interpret the test results, you aren't using your GPU at all, yet GPU memory is also more than 60%. Something is weird.

Can you post a screen shot of Task Manager, showing your CPU usage by processes, in order to highest to lowest?


----------



## WereBo (Apr 5, 2008)

The CPU temps look fine for an AMD, but your graphics-chip is dangerously high at 98C. I can't see a graphics-card so I'm assuming you're using the integrated onboard chip.

Also, I can't see any spare space for an extra fan on the back so, unless there's a fan-mounting space on the front somewhere, it seems that all you can use is a 'PCI-slot case cooler' (*Examples*) - It might be worth replacing the existing rear-fan with a higher efficiency one, to shift more air, though the downside usually being more noise.

The power-cables are also a bit of a mess and might well be disrupting the airflow across the board-mounted heatsink, in the top-left of the mobo in your photo. If the metal cage at the top-left of the photo has enough free space (and assuming there isn't a front-fan mounted there), try routing as much of the excess wiring into that space.


----------



## music man (Dec 13, 2012)

I'm running recording software called "Reaper", which is also doing video. You can see in my task manager it's at the top of the list for CPU usage. 

My GPU temperatures have reached as high as 99 with this program open, even if I'm not actively using it.


----------



## music man (Dec 13, 2012)

So is the GPU cooled by the same (somewhat dirty) fan as the processor?

I am using the onboard graphics chip. 

I'll try getting those cables into the space you pointed out, WereBo. 

I'm considering reapplying the thermal compound, but I'm not sure what to use to clean the old glue off (one guy on youtube suggested "Goo Be Gone"). Anything else I should know about that process? What's a good thermal glue?

Thanks!


----------



## The_Janitor (Sep 10, 2012)

It's called "thermal compound", or "thermal paste". The two I know of are Arctic Silver and ... well I forget the other one because I don't use it, but it's called "ceramic" something-or-other.

And no, the GPU does not share the HSF (Heat Sink Fan) with the CPU. If you are using onboard graphics, it probably has a passive metal radiator, which also could use some thermal compound.

I use 90% rubbing alcohol for cleaning computer parts. There are others to use, but I would be careful about using any kind of non-tested solvent. For example, did you know that ammonia will melt the plastic electronic "runs" in a keyboard? I found this out one day when cleaning my $80 keyboard with Windex.

Even after you clean everything and reapply the thermal compound, you may still be overheating the GPU as it appears that software is more than what that GPU can handle for an extended period of time. Heat like that will eventually kill-off a GPU and therefore possibly the motherboard, so it might be a good idea to purchase an add-on video card; even a low-quality cheap one (with an active cooling fan) would be better than what you have now.


----------



## music man (Dec 13, 2012)

Thanks for your response Janitor. I just can't see where the video card/GPU is on this motherboard, unless it's hidden behind the fan/heatsink or hidden somewhere else. I know it's an NVIDIA GeForce 9100 video card.


----------



## The_Janitor (Sep 10, 2012)

The photo is poor, but I think it's the large chip towards the upper right corner of the motherboard, but not the one that's actually IN the corner. Put your finger on it. If it crackles and smells like burning flesh, then that's your GPU.


----------



## WereBo (Apr 5, 2008)

You shouldn't need to replace the thermal-compound anywhere, the low temps at idle prove that's OK. However, you do need to drastically reduce the 'under load' temperature of the GPU.

The only way that can be done is to increase the airflow, either with extra fans or, at the extreme, dismantling the PC and fitting it all into a larger case - If the worst comes to the worst, remove the case side-panel and aim a mains-operated desktop fan at the board.


----------



## Tyree (May 10, 2009)

As aboive ^
Your CPU temps are OK and reapplying the thermal compound is not going to affect the GPU temps.


----------



## WereBo (Apr 5, 2008)

Is there any way you can drop the visual-quality in Reaper? That might drop the temp. by a few degrees or so - Alternatively, are there any options (in the 'Options'/'Preferences') to use the GPU for processing work? If so untick it (Some software can use the GPU as a maths-processor for number-crunching).


----------



## GZ (Jan 31, 2010)

Hmm... That is an nVidia chipped board, the GPU is integrated into the SPP/IGP (North-Bridge Chip)... There is usally a heatsink on this chip to keep temperatures down. I cannot make it out in the photo. The NB chip is usually close to the CPU and Memory slots... 

Is there a heatsink in that general area? If so, is it firmly mounted?


----------



## music man (Dec 13, 2012)

Could the CPU fan be speeding up because the GPU is overheating?

The fan has sped up twice today. At the time that it sped up, the GPU was between 92c and 94c. Last night I cleaned the fan and heat sink and reapplied thermal paste for the cpu fan.

Thanks to user Makinu1der's help, I have located the NVIDIA 9100 GPU on my motherboard, and it's pictured below. I've read that these cards commonly overheat. I've never seen temps on it below 89. 

I'll check that the GPU heat sink is well seated. This computer has unfortunately been moved several times, including long car rides. I'll also try reducing visual quality in my sound/video software, Reaper. However, the fan speeds up even when I'm not using Reaper.


----------



## GZ (Jan 31, 2010)

When the computer is running, does that heatsink become hot?

It could, I suppose. I am not exactly certain how the fan speed control works in this system. I have seen stranger things though.


----------



## music man (Dec 13, 2012)

I try not to stick my hands in the computer while it's running for fear of electrocution, but I went ahead and touched the GPU heatsink, and it's hot. It burns me after about two seconds.


----------



## GZ (Jan 31, 2010)

That doesn't seem to be a very efficient design, and the heatsink on the NB chip doesn't look up to the task.

I suggest trying to keep some of those wires out of the way, hoepfully increase airflow over that area of the board. 

There is also the route of aftermarket NB heatsinks (active and passive) that can be tried.


----------



## WereBo (Apr 5, 2008)

If you can tidy the cables out of the way, you could try replacing that rather wimpish-looking heatsink with something more efficient - Link to examples

You'd need to do a bit of research to find what will be suitable for your specific motherboard though.


----------

