Computer issue - HELP PLZ!!!

[Foul_Play]

Ok my computer has developed a bad fault which has been driving me MAD!

So heres the specs:
AMD FX-8120
8gig ram
MSI R7850
2TB Sata 6 drive
Traktor audio 6
antec earthwatts EA430-D

This PC has been running for the past 2 years with no issue that is until it started acting up recently. The problem occurs in bf4 and extends to the windows 7 desktop.

I can play bf4 with no issue for about 5 minutes before the cpu fan (im pretty certain) throttles down and there is a high pitch scream which I cant figure out if its coming from the PC or the speakers. Bf4 will give me about 5 fps whilst this occurs, wont recover and I'll quit back to windows and the PC will recover after about 5 minutes. It will be generally sluggish in windows, browsing etc. It tends to hang for a split second when closing windows and saving documents etc. It NEVER crashes just performs badly.

I replaced a hard drive as it was on the way out and I thought this could be the problem. Although this helped the running of the PC generally it hasn't fixed my Bf4 woes and there is a noticeable lack of performance in windows since this sound/problem has occurred. I have put the PC under load in windows using prime95 and it throttles down, screams and really struggles like bf4. I have tried to monitor whats going on under load and idle etc with HWMonitor (and the likes) but alots of the readings are wrong. I'm no expert but after reading similar threads people suggest psu/gfx.

Can anyone help me to get to the bottom of this, its driving me mad!!

 

[Outlander_04]

unplug the speakers completely and work out where its coming from

 

[Foul_Play]

I have unplugged the speakers and the whine is still there under load. My hearing is quite bad but I'd guess that its coming from the CPU or PSU fan. Very high pitched and quiet - I can hear it more from the front of the PC even with the side of the case off. It appears to be coming from the back top of the pc around the CPU/PSU

 

[Vic 40]

Tried the next to see how temps are?

Download the next program=hwinfo32,

http://www.hwinfo.com/download32.html

You can open hwinfo32,after that open the sensor window by marking sensors=V.
I like it and is often accurate with sensor readings.

Give this because maybe the cooler fan is dying and the cpu get's to hot.Voltage readings are afaik also accurate so you could look at these too.

 

[Foul_Play]

I have monitored it for a few days now using a combination of prime95 and speedfan/hwmonitor/Hwininfo64. Only running one of the latter at a time as I hear this can effect the readings. I found speedfan to be the most accurate on my system after quickly going back to bios and comparing the readings regarding the CPU temp.

Underload (prime85 running on stress test) I get,
Temp1 - 30c (system overall temperature?)
Temp2 - 70c (not sure what reading this is but it tends to be the highest) - Burning symbol
Temp3 - 66c (not sure what this is either) - Burning symbol
HD0 - 33c (I'm guessing this is hard drive)
GPU - 24c (Graphics card I guess)
Core - 55c (CPU temp at a guess - I read these AMD FX-8120 are good to about 60c)

On idle (sat in windows with minimal apps open, just speedfan drivers etc)
Temp1 - 30c
Temp2 - 52c
Temp3 - 42c
HD0 - 35c
GPU - 32c
Core - 32c

Just before I ran this particular test I changed a setting in the bios which auto controlled the CPU Vcore voltage with regards to temperature. I guess when the CPU is hot, it drops the vcore voltage to cool it down? Anyways I DISABLED this and it seems to run alot better in windows, I haven't tested any games yet. Before I disabled this setting the PC was choking massively i.e 2-3 minutes opening a browser window, big hangs when closing windows etc

I have ordered a good quality heatsink and fan as I hear the stock ones are naff and I'll get that in a few days.

 

[Outlander_04]

check that nothing is obstructing the cpu fan . A wire nearby ......
Check the heatsink is firmly attached and you cannot move it at all

 

[Foul_Play]

I have just stipped down the PC to have a closer inspection and clear out some of the dust. There was a heavy build up in the CPU heatsink of dust. I've cleared what I could without taking the heaksink off the chip as I have no thermal paste. Heatsink is properly solid on the processor. Cleaned out the gfx card as that was mega clogged up with dust and removed and dusted the ram. Put it back together and I'm getting -5-10c difference in idle temps. Underload its actually a couple of degrees hotter overal but feels like its running better