Power Consumption Results
Important Preamble
In addition to AMD's new Ryzen 5 processors, we also tested the Ryzen 7s once more, given a number of platform changes, the Windows 10 Creators Update, and new drivers. This means the results from our Ryzen 5 review aren't comparable to what we presented in the Ryzen 7 launch story. Fortunately, the differences are very small.
The power consumption results are based on numbers provided by the MSI motherboard’s power supply sensors. We used a special low-pass filter that eliminates brief peaks and valleys, as well as an adjusted average calculation method. The individual clips last only two minutes, but the bar graphs are based on the full 15-minute tests needed for an accurate measurement.
Power Consumption Comparison: Ryzen 5 Processors
The data we're presenting is the result of lengthy test intervals. These are necessary to avoid (or at least minimize) sporadic measurement errors and the influence of unwanted fluctuations.
The findings get interesting once the cores are stressed with a higher load. Power consumption goes up significantly, and there’s a large difference by the time we hit the stress test.
Power Consumption Comparison: All Processors
The following chart includes all of the Ryzen models we've reviewed thus far at idle. The differences between them are very small. In fact, they can only be measured reliably with a 15-minute test run.
AMD's six- and eight-core models demonstrate similar power characteristics. Because there's really no difference between them, we can only assume that the CPUs with disabled cores didn't have them cut off electrically. As a result, they're still being supplied with power.
It’s anyone’s guess at this point whether it'll ever be possible to activate disabled cores/cache against AMD's wishes. More than likely, though, the company took pains to prevent that kind of modding.
Even though AutoCAD is predominantly single-threaded, the differences between Ryzen processors prove to be marginal once again. They are probably attributable to variations in chip quality and clock rate more than anything else.
Under heavier loads, the larger Ryzen models are left behind. AMD’s Ryzen 7 1700 comes closest to the architecture's sweet spot due to its lower clock rate.
A similar picture emerges during the stress test. AMD’s Ryzen 7 1700 with its 16 threads and low frequency beats the 6C/12T Ryzen 5 1600X.
What we’ve found in our Ryzen 5 tests fits in well with what we’ve known and suspected based on our previous experiences with AMD’s Ryzen 7 processors. Mainly, the Ryzen 5s aren’t any more or less efficient than the eight-core variants. This leads us to two conclusions. First, the Ryzen 5's die quality isn't any worse than what you get from Ryzen 7, and it doesn’t negatively impact efficiency or drive up power consumption. Second, disabling cores to yield a Ryzen 5 doesn’t result in better efficiency, which makes it highly likely that these deactivated parts are still supplied with power.
The power consumption results across all of AMD's Ryzen processor models are solid compared to Intel's equivalent CPUs, except at idle. AMD’s efficiency really isn’t any worse than Intel's, provided that you present Ryzen with a threaded workload able to fully utilize the architecture.
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