Phenom II X4 920 Overclocking Experience
To find out the overclocking potential of Phenom II X4 920 processor we put together the following test platform:
- CPU: Phenom II X4 920 (Deneb, 2.8GHz, 6MB L3);
- Cooler: Scythe Mugen with Noctua NF-P12 fan;
- Mainboard: Gigabyte MA790GP-DS4H (AMD 790GX + SB750);
- Memory: GEIL GX24GB8500C5UDC (2 x 2GB, DDR2-1067 SDRAM, 5-5-5-15);
- Graphics card: ATI RADEON HD 4870;
- HDD: Western Digital WD1500AHFD.
First of all we checked out how the CPU would overclock without increasing its core voltage over the nominal 1.35 V. It turned out that our sample could overclock to 3.36 GHz by simply increasing its clock generator frequency. Even without any voltage adjustments the system remained stable at up to 240 MHz clock generator frequency setting.
Note that we had to lower the multipliers for the HyperTransport bus and integrated North Bridge frequencies to 8x, so these frequencies stayed at 1920 MHz, which is pretty close to their nominal values. The same way we used 4x multiplier (corresponding to DDR2-800 in nominal mode) for the memory frequency. So, we overclocked our memory to the level of DDR2-960 SDRAM.
However, the results obtained without any voltage increase are only interesting if you are not ready to deal with considerably higher power consumption and heat dissipation during your overclocking experience. We decided not to stop at that point and pushed the CPU core voltage to 1.55 V to hit even greater results.
Increased Vcore provided additional room for further CPU frequency growth, so we could get our processor to run stably at 3.72 GHz. It was obtained by raising the clock generator frequency to 266 MHz.
I have to point out that once we confirmed processor operational stability in this mode by running OCCT 3.0.0.b23 utility for one hour, we decided to overclock the North Bridge built into this CPU, too. When we increased its voltage to 1.4 V, it could work just fine with 8x multiplier, i.e. at 2120 MHz frequency.