CPU Intel Core i5 2500K (3.3GHz)
Motherboards
- GIGABYTE G1 Sniper 2
- ASRock Extreme4 Gen3
- MSI Big Bang Marshal
- ASUS Maximus IV Extreme
- GIGABYTE Z68-UD4
- Foxconn Rattler P67
- ASUS Sabertooth P67
- ASUS P8P67 (LGA1155)
- Foxconn P67A-S
- ECS P67H2-A (Black Extreme)
Memory 4GB Kingston HyperX Genesis CL9 1600MHz
CPU Cooler Noctua NH-D14
Graphics ZOTAC GTX 460
PSU OCZ Fatal1ty 750W

All P67 Sandy Bridge motherboards will be benchmarked against each other using the Intel Core i5 2500K. The maximum overclock will also be included within the proceeding benchmark tests to identify performance gains as a result of tweaking CPU clock speed via the multiplier.



Overclocking

As previously mentioned in our Intel Core i5 Sandy Bridge Roundup - overclocking is achieved by altering the multiplier rather than the BCLK. So the BCLK stays at 100MHz and the multiplier is modified. So if we have 100MHz on the BCLK and 40 for the multiplier this will obviously output 4GHz. We chose to use the Intel Core i5 2500K across each of the motherboard tests and indeed for the overclocking due to its unlocked multiplier.

With overclocking simplified on Sandy Bridge, this means that achieving the best overclock couldn't be easier. CPU voltage and multiplier just need to be modified accordingly. The ultimate milestone is 5GHz on air cooling for the Intel Core i5 2500K, my immediate action was to set the multiplier at 50 and increase voltages to sustain this overclock. I soon began to have problems with this, altering PLL, VTT and increasing the CPU voltage to 1.5v still wasn’t enough to allow for a stable overclock. It did boot but during stress testing using LinX I was soon given a BSOD.

So, from here I began moving the multiplier back whilst keeping reasonably high voltages in place. 4.8GHz (40 x 100) was ultimately the overclock result that was stable. CPU voltage being 1.47v and PLL 1.9v. Note CPU-Z screenshot displayed the voltage incorrectly… as you will appreciate overclocking 4.8GHz would not be possible on 1.044v!