Results: Power, Heat and Efficiency
We manually enable all of Intel’s C-states before running our performance benchmarks and power tests. However, Gigabyte’s Z97X-UD5H imposes this CPU's top Turbo Boost ratio whenever any load is applied. We see the platform jump from a reasonable 46 W with its cores mostly idle (power settings working) to a more extreme 192 W fully loaded with eight threads of AVX-optimized Prime95.
The above result from Gigabyte's Z97X-UD5H is a perfect example of what happens when a motherboard forces the top Turbo Boost ratio with all cores utilized, and it’s also the perfect example of why this CPU is supposed to drop from 4.4 GHz to 4.0 GHz at that load level. Intel calls this an 88 W processor!
Anyone who wants to argue against my suggestion that forced Turbo Boost ratios represent overclocking need only look at the temperature results from Gigabyte’s Z97X-UD5H, above. Thanks for making my point guys!
Now, let's play devil's advocate. What did Gigabyte’s overclock yield? Per our measurements, a 2% gain in performance with a 12% loss in efficiency. That loss in efficiency boosts Asus' Z97-Pro(Wi-Fi ac) to the top of this chart.