Intel Core i7-8700K CPU Review: Page 5 of 6
Posted by Damon Bailey on Thursday, October 5, 2017 - 9:00am
Power Consumption & Overclocking
Power consumption on the i7-8700K quite surprised us with a very modest 45W from the wall at idle and is quite a bit lower than previous systems. On the load side, we see more typical power usage of 174W from the wall, landing right around our other six-core systems.
We start out from our base 3.7 GHz that often boosts well into the mid 4 GHz range and try to push the CPU as far as we can.
After some trial and error, we were able to reach a top clock speed of 5.3Ghz at 1.43V. This is pretty impressive in and of itself with 6 cores, but we found actual performance was much lower than expected, likely from internal throttling similar to what we experienced recently with our HEDT Sky Lake-X testing.
It appears the very dense silicon means our days of just cranking the voltage and hoping something doesn’t melt are well behind us, and peak performance is achieved with a more finessed balance of clocks and voltages.
We next set out to find our best performance, tested with Cinebench R15 while overclocked.
In the end, we were able to achieve our best Cinebench score of 1602 at a clock speed of 5.1GHz at 1.31V with ram at our XMP speed of 3200MHz. This is more than a 200 point increase over out stock 1393cb score, a 15% increase in score. It’s actually pretty interesting to see this core so close to the scores of a few 8-core CPUs like the i7-5960X and the i7-7820X also listed in the chart.
Power consumption during out 5.1 GHz test runs hit 230 watts from the wall, about 50W higher than stock, but certainly not that bad at all.
Temperatures during our stock runs hovered in the upper 60C’s to low 70’s and overclocking raised this to a warm but still safe mid to upper 80C’s. While Intel is using a thermal paste again this generation, we found the temperatures to be a bit more manageable this go around, coming in around 10C lower across the board from stock to overclocked.