Intel Haswell i7-4770K & i5-4670K Review

System Power Consumption

Our power consumption numbers are broken down into two categories: one which simply stresses all of the CPU cores with WPrime and another which puts a high amount of load on both the CPU cores and the IGP. The latter will only be included if a given processor includes a dedicated internal graphics sub-processor.

For the CPU power consumption test, we use the standard testing system (with an NVIDIA GTX 670 installed) and wait until the system and discrete GPU are at idle speeds in order to log the idle power consumption. After this, WPrime 1024M is looped for 15 minutes while the power consumption is logged with a calibrated power meter to determine the peak watts.

IGP power consumption testing follows very much the same route as above but with some changes. First and foremost, the GTX 670 is removed and the video output is run through the processor’s graphics engine. In order to fully load the graphics cores and the primary processing stages within the CPU, we run the Unit Benchmark (in DX9 mode) from Civilization V for exactly 15 minutes.

Please note that after extensive testing, we have found that simply plugging in a power meter to a wall outlet or UPS will NOT give you accurate power consumption numbers due to slight changes in the input voltage. Thus we use a Tripp-Lite 1800W line conditioner between the 120V outlet and the power meter.


Many of Haswell’s architectural advances target power consumption and performance per watt. Considering the spectacular performance we have seen on previous pages, these results are right in line with expectations but they still set a new high water mark for efficiency. Not only is Haswell in a different dimension than comparable AMD processors (the FX-8350 for example) but it wins by a good margin against similar previous generation Ivy Bridge and Sandy Bridge CPUs. We really couldn’t have asked for more.

One interesting metric we see above is the small difference between the i7 4770K and i5 4670K. While both are 84W TDP processors, the i5 runs at lower speeds and has 2MB of its cache disabled so it naturally consumes a bit less power.


Even in IGP power consumption, the 22nm Intel Haswell processors are able to make quick work of the 32nm Trinity APU line from AMD. All things considered, these are once again some impressive results, especially against the i7 3770K.