A8-3870K vs. Core i3-2105 CPU Review

Overclocking

Since the A8-3870K comes with its clock multiplier unlocked, this gives us an extra option to push the clock of this CPU. Its default clock multiplier is x30 with a base clock of 100 MHz, generating its internal clock of 3 GHz (100 MHz x 30). We were able to easily increase the clock multiplier to x34.

Increasing the base clock, however, was very difficult, at least with the motherboard we had available (Gigabyte GA-A75M-UD2H). This is because all clocks on the system (integrated memory controller, PCI Express lanes, SATA ports, graphics controller, memory, etc.) are tied to the CPU base clock.

We could increase the base clock only up to 108 MHz, but since we had the clock multiplier at x34, we could put our A8-3870K to run stable at 3,672 MHz, an impressive 22.4% increase in the CPU’s internal clock rate.