PC registering lower CPU clockspeed than what it should

[Tombstone_actual]

Ok so one of my friends got himself a new PC few months back, was in a pretty tight budget, so here are the specs:
Mobo- Gigabyte 78Lmt s2
CPU- Amd FX 4130 @ 3.8ghz
RAM- EVM 1333mhz strontium 4Gb
HDD- 500gb WD
GFX- GTX 650Ti boost
PSU- Coolermaster thunder 600W
OS- Win7 64bit
The processor mentioned is my previous 1 and a half years old one that i sold to him. Now, the problem is that the clockspeed that the computer registers is only 2.81ghz(when viewed from my computer properties/Dxdiag), isn't it supposed to be 3.8ghz? Every game works just fine, no issues whatsoever. Is it the processor's fault? Or is it the motherboard's? Can the motherboard downclock the CPU when not performing heavy tasks and all?
I had almost exactly the same configuration a year and a half back and my motherboard, Gigabyte 970ADS3 used to register 3.8ghz as it should. I've played games like Battlefield 3-4, Skyrim, Cod Ghosts, Nfs rivals, Far cry 3, Tomb raider..etc. without any glitch at a decent graphics and resolution. Also tried the CPUz..its registering 2812.7mhz
Please help me out fellows and thanking all in advance

 

[Lmah]

If the power saving features are enabled it is underclocking while not being stressed.

I would also check the bios and see if the multiplier is set correctly, I remember this happening on socket A occasionally not sure if it's an issue with current AMD motherboards, I highly doubt it, but it doesn't hurt to check.