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Power Consumption
Power consumption measurements are always a bit tricky, but as long as the 12V supply (EPS) readings and the sensor values of the power supply of the mainboard plus voltage transformer losses plausibly coincide, everything is fine. Therefore, we again rely on the pure package power to avoid possible influences from the motherboard. The values of the PWM controller are really very reliable if taken as averages over a period of a few minutes.
At idle, everything is perfectly fine. Both the stock and overclocked Core i9-9900K sip power. The fact that the Ryzen 5 2600X lands at the top of our chart is confirmed by our bad sample. This is definitely not a general AMD problem though, as the Ryzen 7 2700X shows. In general, however, all the CPUs are quite economical.
Both -9900K configurations are still in good shape during the CAD workload: the chip's power consumption is only slightly higher than the Core i7-8700K. So far, the very high voltage needed for stable operation does not make a disturbing impression. Everything is still in the green.
Power consumption is also within the expected values during the gaming loop, especially since the game does not fully utilize all cores. Although a comparison test with Assassin's Creed Origins did yield much higher values (up to 20W more), that game is so poorly optimized that we measure completely different values each time.
Five measurements with five strongly diverging results are not something that would be apt for a fair comparison. However, at 5 GHz, the Core i9-9900K never really crossed the 100W limit, so it was still cool enough to make ends meet. At least for games.
But power becomes more of an issue in some productivity applications because a constant load on all cores at high clock rates is almost too much. And to be clear, the Core i9-9900K gets super hot faced with Prime95 and AVX instructions (205W stock, 250W overclocked), exceeding the specified TDP.
We measured 137W (232W) during the Cinebench test, and we topped 145W (241W overclocked) under the larger Blender workload. We even pushed past 120W (198W overclocked) with various CAD plug-ins for Creo and SolidWorks. The limits of normal all-in-one compact water cooling solutions are in sight during standard operation at 4.7 GHz on all cores, but you can easily overwhelm cheaper AIOs during overclocking.
Finally, and because we like the additional detail, here are the line charts corresponding to our long-term measurements.
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