Thermals and power are directly related. Higher power consumption means higher heat, naturally, and the ability to get rid of that energy more efficiently also directly correlates with power leakage reduction.
Our power tests use Blender, FireStrike, Total War, Cinebench, and Prime95 for a mix of real-world and synthetic applications, ranging from stressful to lightweight in power consumption.
Intel i7-8700K Power Consumption: Blender
Starting with Blender, the i7-8700K pulls about 96W down the EPS12V cables in its stock configuration, permitting the CPU to complete the render in 26.6 minutes. The R7 1700 pulls about 80W in this configuration, completing the render in around 29 minutes. More on that later. Overclocking the i7-8700K puts us up to 130W when at 4.9GHz and 1.4V on our magically awful chip, which is right around where our overclocked R7 1700 lands for power. The i7-7700K stock CPU measures at 74W for this test, marking it about 20W lower than the 8700K. A lot of this has to do with motherboard and BIOS, as always, so these numbers could change.
Intel i7-8700K Power Consumption: FireStrike
For the FireStrike Physics test, the 8700K plots at 68W under its stock configuration, or 106W when overclocked. For comparison, the R7 1700 draws about 55W stock and about 95W when overclocked. As for the 7700K, that’s sitting at around 50W with our Gaming 7 motherboard on the latest EFI.
Intel i7-8700K Power Consumption: Total War
Total War: Warhammer power consumption (using the new bench) lists us at 51.6W, flanked by the 7700K (44W stock) and 1700 (46.7W), with the overclocked 8700K drawing an additional ~30W at 4.9GHz / 1.4Vcore.
Intel i7-8700K Power Consumption: Cinebench NT & 1T
Intel i7-8700K Power Consumption: Prime95 29.2 8K
The Prime95 29.2 sample above is particularly interesting: What's not shown is that the X299 CPUs occasionally spike to 50A (615W) draw, but then trip OCP and crash. This can happen nearly instantaneously, causing jumps in power consumption that spike as much as +25A without warning, hence OCP. We did not encounter this behavior on the 8700K, but are remaining alert.