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    CPU fan is running high after rebooting




      I have a Q6600 CPU and a DG35EC motherboard and when I restart my PC after an update or whatever, fans are running high (I think it's the CPU fan). I have three fans (except PSU fan): 1 front fan, 1 at the back and the CPU fan. And it's only when I have to restart my computer. CPU temperature seems normal and I changed the thermal paste: same problem. I tried a BIOS update: same problem.


      Any suggestions?



        • 1. Re: CPU fan is running high after rebooting

          Hey there.

          Its normal that the fan(s) are running high during the in initial stage of the boot. Actually what happens is that once the temperature monitoring utilities kick into action, it will read the current temperature of the cup and various portions of the motherboard. Once that starts happening, your fan  speed is now controlled by the feedback of temperature of the cpu. Now the PSU fans are not dynamically controlled like that. And worry not, even my fans run at full speed till the time the ACTUAL TEMPERATURE of the processor is read and the fan speed is reduced accordingly. Initially, it assumes the temp to be max and thus fan speed is full.

          By the way, your MoBo is not fully compatible with processor. So i suggest go to the below link and check if the AA# mentioned there and yours revision matches


          1 of 1 people found this helpful
          • 2. Re: CPU fan is running high after rebooting

            Thanks for the information and for your rapidity. But I know it is normal that when the computer boots or reboots, fans are running high at the beginnning. But I'm not sure it's normal because when I reboot, CPU fan is running high, it is very noisy and it continues also when I'm in Windows. I must completely turn off my PC, wait for 5 minutes and turn on. In this case, fans turn normally and they are not noisy.


            I will check the link you provide me. Thank you!

            • 3. Re: CPU fan is running high after rebooting

              Well under that case i guess your system is overheating. Does your system restarts/shuts down automatically? and do u get any msg like "system restarted due to overheating"? Also check the temperature and fan rpm once you've kept ur system on for long time. This you can do by getting into bios and going to ADVANCED tab, and then to HARDWARE MONITORING. Post the temperature and fan rpm if you can.                         

              • 4. Re: CPU fan is running high after rebooting

                Also since you have chasis fan very near to your processor fan, it might result into turbulant sound. So rely on sound anytime, check the data that you can find in bios

                • 5. Re: CPU fan is running high after rebooting



                  Thanks again for your rapidity. I don't think my system is overheating. I changed thermal paste and it does the same thing. I'm not at home but I remember that I checked CPU temperature in Hardware Monitoring and it was less than 60 Celsius degrees (can't remember the number exactly). But you give me an idea. Yes, my chassis fan (at the back of the computer) is maybe too close to CPU fan. I will do some tests with this, thanks.


                  For the compatibility of my CPU, I know that I have a BIOS after the 0072 recommended, but I will do the most recent update tonight.


                  But it's really strange because the problem happens only when I restart... Of course, the noise continues except if I turn off completely the PC and I turn on some minutes later. And a year ago, I had another brand of motherboard and I did not have this problem.. Strange.


                  I'll do my tests and I'll give feedback!


                  Thanks for your time.

                  • 6. Re: CPU fan is running high after rebooting

                    Oh my pleasure helping you. Computer hardware interests me and when not working properly, bothers me too.

                    I would also recommend you to check weather the chasis fans are attached firmly or not (the screws of those are tightened properly, although dont over tighten it).

                    Since you have done bios update recently, i doubt if the newer version is available. Still give it a try. Also i suggest you keep atleast one fan which ventilates the chasis (hot air from inside should be thrown out). Apart from that, your system seems to be alright ! It could be the sound of mechanical vibrations that can come dude to loose fans, loosely connected hardisks, smps or cd drive. Although it sounds dumb, sometimes thats the cause of noise


                    Waiting for the temp data.

                    • 7. Re: CPU fan is running high after rebooting



                      I'm studying in computer science, in networking. It's my last year I have good knowledge but sometimes, an external idea is very helpful! I also repair computers at work but, when it's mine, I often have customers' problems in my head, more than mines, hehe.


                      I will be back soon!

                      • 8. Re: CPU fan is running high after rebooting

                        Some updates probably cause this more than others.  The malware updates in particular should do this.  Otherwise I would ask how long you have been using the Q6600.  I had been wondering if I would really be able to move one to a DG965WH board.  It is listed but seems better suited for the DG45ID where it currently is.

                        • 9. Re: CPU fan is running high after rebooting



                          I did not have a lot of time to do check ups. So, I have the most recent BIOS update, CPU temperature is stable at 59 Celsius degrees and thermal paste is ok, but I do not try something with chassis fans.


                          I'll continue tests and bring back results soon.

                          • 10. Re: CPU fan is running high after rebooting

                            I have an AMD processor and also have my fans running higher after rebooting (or just turning on). I think it is a normal situation.

                            • 11. Re: CPU fan is running high after rebooting


                              Its totally normal that fans are running high when you start your system. Because the drivers that control the speed of fan can get "working" only when the operating system boots up completly. So till that point of time, your computer thinks the worse (the cpu is ultra hot) and spins the fan at full speed. Its better to think worse than to assume CPU is cool and spin it slowly. The latter contains risk

                              • 12. Re: CPU fan is running high after rebooting

                                Thats good to hear that your system temp are stabilizing.. I would recommend to put only 2 chasis fans. One that gets cool air in and the other should throw away hot air out. Both the fans should be on extreme corners of the chasis try putting the 2nd one (exhaust fan) on top portion (under CD drive), because hot air rises and cold air sinks

                                • 13. Re: CPU fan is running high after rebooting



                                  I did not have a lot of time to come back here. I don't think that is a normal situation. I understand that the fans may speed up after rebooting but, when I am in the OS, fans continue to turn very high and that's very, VERY noisy.


                                  I took off one of the chassis fan and the problem is always here.  I will reverify if there is a new BIOS update but I think all the tests are done but unsuccessful...


                                  Thanks for all your suggestions.

                                  • 14. Re: CPU fan is running high after rebooting

                                    This may sound too simple, but be sure to check the BIOS configuration re: fan behavior.

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