CPU Overheating

[andreinoplay]

Hello everyone, I have a problem, my processor runs at about 57 ° C idle and at 85+ when I'm playing (of course at that point the computer shuts down). It Happens to me since I passed by this configuration:

CPU: Intel Core 2 Duo E6550 2.33 GHz
Motherboard: Asus P5GC-MX/1333
GPU: Nvidia Geforce 8800GS
RAM: 2x1GB Kingston DDR2 (can't remember the model)

to this one:

CPU: AMD Athlon 64 X2 4800 +
Motherboard: MSI K9N Ultra
GPU: Asus GeForce GTS250
RAM: the previous one + 2x1GB Kingston DDR2

The new components were my brother's (who has bought a new PC), so they are "used". I don't think it could be a ventilation problem, because my case is much bigger than the one he had and it has many more fans (maybe too many xD). I thought it could be a thermal paste problem, since mine was completely dry, so I replaced it, but absolutely nothing has changed; I also cleaned the heatsink and the CPU fan, still nothing. Could it be that the fan and CPU cooler are ruined? I also noticed that, from what Speccy says, the CPU Fan runs at 1770RPM, on average, which seems a bit slow to me (but I could be wrong), because my brother's one runs at 2000 something.

also, should I enable AMD Cool and Quiet?
and what program should I trust to see temperatures?
Speccy says 57°C, Speedfan says 40°C, BIOS says 40°C, and Everest 45-50°C(CPU) and 60-70°C (single cores)


Thanks in advance

 

[Uther39]

Core Temp and HW monitor, what pc case are you using with what fan configuration ?

 

[andreinoplay]

My case is a Thermaltake Xaser III (http://www.tomshardware.com/reviews/spring-case-madness,623-50.html)
i've got 2 80mm fans blowing air out, and another 4 fans blowing air in
also I'm using stock heatsink and CPU Fan

these are the temps http://i52.tinypic.com/2d8n8no.jpg
in the BIOS it's still 40°C
and the computer keeps shutting down when playing