Overclocking the CPU and GPU
CPU overclocking
Some tasty overclocking with just a sprinkling of extra voltage. 4.75GHz was stable for the most part, too. The overclocked figure is about 100MHz higher than on the ASUS P67 PRO board using identical settings. Anyway, we re-ran HEXUS.PiFast and wPrime numbers.
The best numbers we've ever had from a 2500K chip cooled by the stock heatsink-and-fan unit.
IGP overclocking
Z68 also lets us boost the speed of the IGP. To this end we ran Just Cause 2 at medium-quality settings and a 720p resolution. We compared the overclocked performance to both a stock-clocked IGP and discrete Radeon HD 6450 card, representing the first rung on the add-in-card ladder.
The default speed is 1,100MHz, once the Turbo Boost has kicked in. We increased the IGP voltage by 15 per cent and managed to hit a solid 1,600MHz, adding some 35 per cent over basic perf. A £35 Radeon HD 6450 512MB is 35 per cent faster still, but we can see there's merit in boosting the Sandy Bridge chip's IGP - it's 'free', after all.