It is about VAIO А but should still help you.
1. Fan whistle/whine at certain speeds (different people experiences this at different fan RPMs/RPM range!)
Cause: Very likely produced by the fan blades as they cut through the air.
Samples: by Poohkie, by thausif, by sheebp, by meloover, by mmm123, http://www.youtube.com/watch?v=iFoUQZ3eoN4.
Solution: None from what I remember. Try different fans/notebooks, the small manufacturing difference it might just ‘solve’ this for you (reduce it till an acceptable level), or you can get used to it.
2. Fan buzzing/humming/droning noise (lower frequencies)
Cause: Fan fault ?
Cause: described by jacksjw as variable pitch whine noise/drone: “It appears that the drone is acoustically produced by the bottom cover's interaction with the bottom intake port of the fan” (see jacksjw’s experiment links below).
Solution: Replacing the fan/servicing the notebook solves this issue, so send the notebook for repair.
3. High frequency electrical whine, CPU/chipset whine kind of noise
Cause: There are many theories about it, but none of them confirmed from what I know.
Samples: by angcasad31 on the Sony Discussion group (the audio file – turn up the volume).
Solution: Disabling the C3/C6 CPU State in BIOS makes the noise go away. I personally confirm this!
If this is very loud sent the notebook for repair (or return it and try a new one).
Solution by Sony Support: How to troubleshoot noise issues specific to the VPCF Series
Note: It is specific to notebooks with i7/i5 CPU.
4. High pitched squeal/whine, Morse code like noise
Cause: Noise picked up by the microphone circuit and amplified by the audio chip. The source of the noise is probable the same as for the “High frequency electrical whine, CPU/chipset whine kind of noise” mentioned above.
Samples: by Joe Bleau on youtube:
Solution: From what I know this was fixed by Sony in the new notebooks. If you experience this with older notebooks, try the temporary, microphone related solution (muting/selecting different input/…) - see by Joe Bleau’s youtube video from above. waitwaitwait reported that his notebook was fixed by Sony repair by applying some shielding pads to the main board.
Solution by Sony Support: How to troubleshoot noise issues specific to the VPCF11 Series
News: New Sony-VAIO-F-Series Encountering Buzzing Or High Pitched Whine Issue?;
No Worries – The Sony-VAIO-F-Laptop Is Okay And Back On Sale
5. The normal fan noise, air flow/air rushing noise or the famous LOUD fan
Cause: Powerful CPU & GPU produce heat, so needs cooling.
Solution: If the fan is at high speed because a high CPU and/or GPU load, that’s normal. It’s the price we pay for the high performance.
If this load is not what you exercise by running known applications then it’s time to check for virus/spyware/… or even time to do a fresh install.
If there is no CPU nor GPU load, the temperatures are high and the fan is still rotating at high speeds, then clean the fan from dust. If it doesn’t help, then it’s time to send the notebook for repair.
6. Constantly varying fan speed (and the associated varying fan noise)
Cause: The way how Sony implemented the notebook CPU & GPU cooling (it’s very efficient, but …).
Solution: None from what I know.
I just hope that Sony will release a firmware in which, at least in case of low fan rotation speed, they increase the hysteresis at least 10 times in order to have a less varying, if not constant, speed. Or a BIOS settings to limit the lowest rotation speed on AC power, which I could tune for my liking (When under load, the varying fan doesn’t bother me).
7. HDD noise
Cause: The way how the supported power states and acoustic management were implemented by the HDD manufacturer.
Solution: The Automatic Acoustic Management (AAM) and Advanced Power Management (APM) configuration needs to be adjusted (use quietHDD or HDDScan for example).
Note: Reducing hard disk noise via AAM can result in significant performance penalty (increased average seek time)!
Links:
> jacksjw’s experiment: link#1, link#2, link#3.
> Poohkie’s F11 owners list with Fan Whistle (direct link).
> “Vaio Laptop fan noise?” on the Sony Discussion group (Noise #1 and #3).