Power efficiency remains important to PC users and Intel and AMD have both made great strides to improve power efficiencies. Today we are looking at the Intel Core i7-3770K with a TDP of 77W, the Core i7-4770K at 84W and the Core i7-4970K at 88 Watts. So, we expect the processors to scale in that order for least to most power use.
Benchmark Results: At idle the Intel Core i7-3770K on the Intel Z77 platform used the most power, which might shock some people since it has the lowest TDP. Intel did some power optimizations on Haswell with advanced ultra low power C-States and they are enabled by default on the ASUS Z97-A motherboard that we were using for the Intel Z97 platform. This just goes to show how much Intel has improved on idle power efficiency over even just Ivy Bridge processors. At load the Core i7-3770 Ivy Bridge processor came in at 116 Watts and the Intel Core i7-4770K used just slightly more power at 122 Watts. The big shocker when it came to power use was the Intel Core i7-4790K as it used about 30 Watts more power at load than the Core i7-4770K. If you are on an older Sandy Bridge processor like the Core i7-2700K you won’t see much of a power difference at all!
We used Handbrake to rip a full 1080P Blu-Ray as our load test, so this is representative of a real world scenario. The Intel Core i7-4790K has great thermal properties, but that extra 500MHz of clock speed means you’ll be using about 24% more power. Most enthusiasts won’t mind that as the thermals are okay, but just something to point out. The power use went up 24% and our performance only went up about 5-15% on many of the common benchmarks.