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CPU fan speed problem

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April 12, 2011 2:34:03 PM

When I got home from work this morning, my PC was shut down and beeping. I have figured out that the CPU fan was running at low speed and this was causing the PC to overheat. I had smartfan enabled and it was working fine until last night. Now it appears that smartfan is not controlling the fan or the fan is bad. The fan is reportedly running at 4100 rpm with smartfan disabled and it is keeping my pc cool. I think it was running at 750rmp with smartfan enabled and the speed was not changing at all.
I was wondering if anyone knows if this could be the fan itself, or the smartfan control on the motherboard. I searched google and could not find anything (i may have not been phrasing it well).
Thanks.

More about : cpu fan speed problem

a b à CPUs
April 12, 2011 2:51:14 PM

(1) Fan will not run @ 4100 RPMs, upper 2xxx is about as fast as I've seen.

To check temps, Download HWMonitor and note temps it will show more than just temps, ie voltages and fan speeds.

Down load prime 95. this is to test how high your temps get to under load.
With Smart fan disabled:
Run HWMonitor leve running for 30 minutes and note temps (core temps more important) are they OK. If OK then with HWMonitor still running run Prime95 in blend mode (default). Watch temps closely for 15 minutes, are they still acceptable. If so leave prime 95 running for 2 -> 4 hours to check stability of your system (many recommend running 4 houres, 2 -> 4 hours is a minium).
Repeat with Smartfan enabled.
It would be helpfull on these kind of problems to identify the MB/CPU at a minumum.
a b à CPUs
April 12, 2011 2:51:43 PM

Seems to be an issue with smart fan it controls the fan speed of load/on board temp. If the sensor is not doing it job correctly it will say the cpu is cool when it is not so the fan will be set at the idle rpms. just a few things to consider.
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April 12, 2011 3:03:30 PM

RetiredChief said:
(1) Fan will not run @ 4100 RPMs, upper 2xxx is about as fast as I've seen.

To check temps, Download HWMonitor and note temps it will show more than just temps, ie voltages and fan speeds.

Down load prime 95. this is to test how high your temps get to under load.
With Smart fan disabled:
Run HWMonitor leve running for 30 minutes and note temps (core temps more important) are they OK. If OK then with HWMonitor still running run Prime95 in blend mode (default). Watch temps closely for 15 minutes, are they still acceptable. If so leave prime 95 running for 2 -> 4 hours to check stability of your system (many recommend running 4 houres, 2 -> 4 hours is a minium).
Repeat with Smartfan enabled.
It would be helpfull on these kind of problems to identify the MB/CPU at a minumum.


HW monitor is what was reporting 4100rpms. Not sure which is which as there are 2. FANIN0 is the one reading 4100 and FANIN1 is reading around 2000.
The temp i noticed when i first rebooted it this morning was TMPIN0 that was reading 106C. With the fan running at 100% it is down to 71C. My core temps seem ok. They are running about 40c to 50c idle. I just downloaded prime95 and will run that test.

Thanks for the replys

edit:
just finished running prime95 for 15 min. Core0 got a max temp of 83c and core3 maxed at 71c. I did notice that TMPIN1 is a lot lower than TMPIN0 and TMPIN2. After running prime95 1 is reading 49c while 0 is 77c and 2 is 67c. Maybe the TMPIN1 is where smartfan is getting its temp data from?

Not going to try this test with smartfan enabled because i already know that its not changing speed at all. it will just shut my pc down when it overheats.

also just noticed THRM that is also reading fairly low, it seems to be reading the same temps as TMPIN2. TMPIN2 cooled from 67c to 34c in a matter of minutes while TMPIN0 and 1 have only cooled a few degrees since shutting off prime95.
April 12, 2011 3:45:58 PM

Just noticed in hw monitor that my 3.3v is only reading 1v. this is most likely the reason the fan is not working. will have to check the psu. thanks for the help.
April 12, 2011 3:59:30 PM

RetiredChief said:
(1) Fan will not run @ 4100 RPMs, upper 2xxx is about as fast as I've seen.

To check temps, Download HWMonitor and note temps it will show more than just temps, ie voltages and fan speeds.

Down load prime 95. this is to test how high your temps get to under load.
With Smart fan disabled:
Run HWMonitor leve running for 30 minutes and note temps (core temps more important) are they OK. If OK then with HWMonitor still running run Prime95 in blend mode (default). Watch temps closely for 15 minutes, are they still acceptable. If so leave prime 95 running for 2 -> 4 hours to check stability of your system (many recommend running 4 houres, 2 -> 4 hours is a minium).
Repeat with Smartfan enabled.
It would be helpfull on these kind of problems to identify the MB/CPU at a minumum.

The RPMs actually go a lot higher in tropical, humid and hot places. It depends quite a lot on the ambient temperature. My Intel stock cooler goes upto 3170 RPM under load to keep temps below 65. My average room ambient temperature around this year comes to about 35-38 degrees Celsius.
a b à CPUs
April 12, 2011 4:50:27 PM

You could be correct. Based my input on 3rd party HSF (I do not even install stock). The only one I installed, and soon removed, was for a C2D and it's spec was 1500 RPMs.

@ mickcris
I could be wrong, but I thought the 3.3 V was the supply voltage for memory (in addition to other Chips). DDR3 is normally 1.5 volts with 1.65 the upper end and NEW low voltage DDR3 around 1.35 V. 1V on 3.3 Volts rail would be two low for the memory voltage regulators on the MB. I do not thing you would be able to boot the computer. DDR2 I think was around 2V and could be powered by the 5V, or the 3.3 V.

More likely an Incorrect displayed value - A quick measurement with a DVM could verify this.
April 12, 2011 5:21:28 PM

RetiredChief said:
You could be correct. Based my input on 3rd party HSF (I do not even install stock). The only one I installed, and soon removed, was for a C2D and it's spec was 1500 RPMs.

3rd party HSFs have lower specced fan RPMs. They probably have better heat dissipation properties than the stock coolers. I personally don't like stock coolers too as just looking at them compared to a 3rd party HSF is like, "Sheesh! What garbage was I looking at!" I am only restricted by my budget and the fact that I would upgrade to Sandy Bridge soon and current LGA 775 coolers won't fit in those sockets.
a b à CPUs
April 12, 2011 5:46:34 PM

Also fan RPM in many cases is based on size, the large it is the slower it can rotate and still move the same or more air. I order the Zalman 9900Max which uses a 120 mm fan and max rpms is around 1800 rmps, my 9700 (on I5-750) uses a 110 mm fan @ max of 2800 Rpms. My 9500 (OCed E6400) uses a 97 mm @ max of 2600)
April 12, 2011 5:49:07 PM

Yeah very true. My one is 80mm, hence the higher RPM. It is quite noisy and inefficient too.
a b à CPUs
April 12, 2011 7:54:40 PM

What motherboard / PSU do you have? Sounds like a problem I had recently, would be good to see if we have similar equipment. I ended up getting an aftermarket cooler and hooking it up to a molex connector.
April 12, 2011 10:00:32 PM

HW monitor was reading is reading my 3.3v incorrectly. i swapped with a spare psu and its still reading the same thing. im thinking it may have be the THRM/TMPIN2 reading so low. Both are now reading 28c after booting my pc with the new psu, but tmpin0 is reading 91c and climbing.

pc is a gateway fx6800-01.


Everest is reporting those temps as follows at 100% fan speed:
TMPIN0 = Aux = 74c
TMPIN1 = Motherboard = 45c
TMPIN2 = CPU = 33c

CPU temp is reading about 10c - 15c lower than my cores. Does this sound normal? Im thinking one or more of these temps is not reading correctly. I'm pretty sure the aux is not right.
a c 104 à CPUs
April 13, 2011 5:06:58 AM

Advice:
1) Run one of the CPU stress applications with your fan at 100% (no fan speed control). If it doesn't crash then everything great except possibly fan control.

2) Do you have BIOS fan control? If so, use it. If you do, ensure you use the correct setting (I needed Voltage set, it defaulted to AUTO which did nothin). If your BIOS fan control is working properly your fan will change speed, otherwise it runs at 100%.

3) Consider getting a good Heatsink +120mm fan if you have stock. A great heatsink doesn't even need the fan as long as you have case fans. (I ran my i7-860 8-threads at 100% with only case fans and my huge CPU heatsink installed. Of course, I used my CPU fans after but they run slowly in normal use.)
4) since Speedfan is software-controlled, a glitch somewhere in other software can potentially cause issues.

READINGS:
your readings sound fine. it's typical to see odd numbers in Speedfan.

Summary:
1. use hardware fan control if available
2. a big heatsink can eliminate the need for a fan, though I'd still add a LOW speed fan (no fan control). For case fans, I'd use two 120mm fans (very LOW speed/noise).
April 13, 2011 7:25:35 AM

photonboy said:
Advice:
1) Run one of the CPU stress applications with your fan at 100% (no fan speed control). If it doesn't crash then everything great except possibly fan control.

2) Do you have BIOS fan control? If so, use it. If you do, ensure you use the correct setting (I needed Voltage set, it defaulted to AUTO which did nothin). If your BIOS fan control is working properly your fan will change speed, otherwise it runs at 100%.

3) Consider getting a good Heatsink +120mm fan if you have stock. A great heatsink doesn't even need the fan as long as you have case fans. (I ran my i7-860 8-threads at 100% with only case fans and my huge CPU heatsink installed. Of course, I used my CPU fans after but they run slowly in normal use.)
4) since Speedfan is software-controlled, a glitch somewhere in other software can potentially cause issues.

READINGS:
your readings sound fine. it's typical to see odd numbers in Speedfan.

Summary:
1. use hardware fan control if available
2. a big heatsink can eliminate the need for a fan, though I'd still add a LOW speed fan (no fan control). For case fans, I'd use two 120mm fans (very LOW speed/noise).


Thanks. I do have it running at 100% right now. I was thinking that the fan control was not working but now im not sure. I have noticed that my gpu and hard drive temps seem high also. I may be the case fan that is not working well and not the cpu fan. I think i will pick up an aftermarket cooler for the cpu anyway.
April 13, 2011 7:30:28 AM

mickcris said:
Thanks. I do have it running at 100% right now. I was thinking that the fan control was not working but now im not sure. I have noticed that my gpu and hard drive temps seem high also. I may be the case fan that is not working well and not the cpu fan. I think i will pick up an aftermarket cooler for the cpu anyway.

I would much rather advise you to check the source of the problem first. You might end up buying an aftermarket cooler for the CPU when the true problem lies in the fans in the case itself and you will end up short of budget when looking for them. An aftermarket CPU cooler is necessary if you plan to do overclocking otherwise the stock heatsink fan does the job pretty well.
April 13, 2011 7:47:21 AM

a4rocks said:
I would much rather advise you to check the source of the problem first. You might end up buying an aftermarket cooler for the CPU when the true problem lies in the fans in the case itself and you will end up short of budget when looking for them. An aftermarket CPU cooler is necessary if you plan to do overclocking otherwise the stock heatsink fan does the job pretty well.


I figured i would just replace thre rear fan and the cpu heatsink/fan and add another fan to the front. there is a spot for a fan in the front, but there is currently not one there. They are not that expensive. Will be about $50 for all 3. It's also always been pretty loud, so getting better fans should cut down the noise some.

Best solution

a b à CPUs
April 13, 2011 12:56:17 PM
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My Bad - should have asked about case cooling. At a minium should have a front fan (blowing in) and a rear fan (blowing out). You can check if this is the primary cause by removing the side panel and using a small house fan to blow in to computer. My system has two fron fans, a rear fan plus a larg 230 mm fan at the top.

Since I'm not an advacate of the stock HSF I concur with replacing it also. The cooler the better.
April 13, 2011 2:46:47 PM

RetiredChief said:
My Bad - should have asked about case cooling. At a minium should have a front fan (blowing in) and a rear fan (blowing out). You can check if this is the primary cause by removing the side panel and using a small house fan to blow in to computer. My system has two fron fans, a rear fan plus a larg 230 mm fan at the top.

Since I'm not an advacate of the stock HSF I concur with replacing it also. The cooler the better.

+1, Having an intake and an exhaust fan is the first rule when building your PC. If you have a front fan opening, get one. Don't just buy another 80mm case fan, get the largest fan that will fit in there (200mm is the front standard). Will ensure higher amount of airflow whilst at the same time keeping quiet. Make sure that you have the airflow balanced with a similar exhaust too.
April 13, 2011 2:54:04 PM

RetiredChief said:
My Bad - should have asked about case cooling. At a minium should have a front fan (blowing in) and a rear fan (blowing out). You can check if this is the primary cause by removing the side panel and using a small house fan to blow in to computer. My system has two fron fans, a rear fan plus a larg 230 mm fan at the top.

Since I'm not an advacate of the stock HSF I concur with replacing it also. The cooler the better.


that seems to be the problem. i stopped by fry's on my way home from work this morning and picked up a couple of fans. its still not great, but better than before. I took the side panel off and blew my Vornado fan into the case and my temps dropped quite a bit (20c on the TMPIN0 and the GPU). i will most likely have to get some more powerful case fans than the ones i picked up. I picked up a couple of cheap ones that seemed like they would move some air, but they aren't working as well as i had hoped. I also was not paying attention and grabbed ones that only had 4 pin connectors. would like ones with 3 pin connectors so i can plug them into the motherboard.

thanks everyone for the help. :) 
April 13, 2011 2:55:27 PM

a4rocks said:
+1, Having an intake and an exhaust fan is the first rule when building your PC. If you have a front fan opening, get one. Don't just buy another 80mm case fan, get the largest fan that will fit in there (200mm is the front standard). Will ensure higher amount of airflow whilst at the same time keeping quiet. Make sure that you have the airflow balanced with a similar exhaust too.


my case has an 80mm front and 120mm back. there was not front fan before. the pc is a refurb gateway that i picked up cheap about a year or so ago.
April 13, 2011 2:56:18 PM

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