this simple trick will activate the 4th core of your amd phenom II x3 thus making it to become amd phenom II x4.
Prerequisite :
- AMD Phenom II x3 710 or 720 Batch : 0904 BPMW, 0904 EPMW, 0904 CPCW
- Motherboard with AMD 790 chipset
- BIOS with capability to change ACC (Auto Clock Calibration) value
To activate the 4th core, simply go to your BIOS Setup and change the value of ACC (Auto Clock Calibration) to “AUTO”
Note that batch with 0904 (years 2009, week 04) are known to be the most stable batch. Other batch might works but might not be as stable as batch 0904.