Ryzen 7 7800X3D: Ahead of Core i9 for gaming at 40% power draw

Methodology: temperature and clock speed tests

The most popular Ryzen 7000 with 3D V-cache obliterates competition in its targeted environment. Intel doesn’t measure up to the Ryzen 7 7800X3D in a comparable price range in terms of speed, and even if someone disregards price and sees the Core i9-13900K(S) as a an apt competitor, when comparing power draw, everyone’s appetite for Intel will go away. Their efficiency is… incomparable, as each is at a different end of the spectrum.

Methodology: temperature and clock speed tests

When choosing a cooler, we eventually opted for Noctua NH-U14S. It has a high performance and at the same time there is also the TR4-SP3 variant designed for Threadripper processors. It differs only by the base, the radiator is otherwise the same, so it will be possible to test and compare all processors under the same conditions. The fan on the NH-U14S cooler is set to a maximum speed of 1,535 rpm during all tests.

Measurements always take place on a bench-wall in a wind tunnel which simulates a computer case, with the difference that we have more control over it.

System cooling consists of four Noctua NF-S12A PWM fans, which are in an equilibrium ratio of two at the inlet and two at the outlet. Their speed is set at a fixed 535 rpm, which is a relatively practical speed that is not needed to be exceeded. In short, this should be the optimal configuration based on our tests of various system cooling settings.

It is also important to maintain the same air temperature around the processors. Of course, this also changes with regard to how much heat a particular processor produces, but at the inlet of the tunnel it must always be the same for accurate comparisons. In our air-conditioned test lab, it is currently in the range of 21–21.3 °C.

Maintaining a constant inlet temperature is necessary not only for a proper comparison of processor temperatures, but especially for unbiased performance comparisons. Trend of clock speed and especially single-core boost depends on the temperature. In the summer at higher temperatures, processors may be slower in living spaces than in the winter.

For Intel processors, we register the maximum core temperature for each test, usually of all cores. These maximum values are then averaged and the result is represented by the final value in the graph. From the outputs of single-threaded load, we only pick the registered values from active cores (these are usually two and alternate during the test). It’s a little different with AMD processors. They don’t have temperature sensors for every core. In order for the procedure to be as methodically as possible similar to that applied on Intel processors, the average temperature of all cores is defined by the highest value reported by the CPU Tdie sensor (average). For single-threaded load, however, we already use a CPU sensor (Tctl/Tdie), which usually reports a slightly higher value, which better corresponds to the hotspots of one or two cores. But these values as well as the values from all internal sensors must be taken with a grain of salt, the accuracy of the sensors varies across processors.

Clock speed evaluation is more accurate, each core has its own sensor even on AMD processors. Unlike temperatures, we plot average clock speed values during tests in graphs. We monitor the temperature and clock speed of the processor cores in the same tests, in which we also measure the power consumption. And thus, gradually from the lowest load level on the desktop of idle Windows 10, through audio encoding (single-threaded load), gaming load in three games (F1 2020, Shadow of the Tomb Raider and Total War Saga: Troy), to a 10-minute load in Cinebench R23 and the most demanding video encoding with the x264 encoder in HandBrake.

To record the temperatures and clock speed of the processor cores, we use HWiNFO, in which sampling is set to two seconds. With the exception of audio encoding, the graphs always show the averages of all processor cores in terms of temperatures and clock speed. During audio encoding, the values from the loaded core are given.


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Comments (4) Add comment

  1. First of all fantastic review. Would it be possible for you in the future to also include X-Plane 12 and DCS World in your benchmark suite? No one ever tests them and while they are very niche they are extremly CPU heavy, moreso than any other game. That would be awesome to see if you could do that.

    1. Thank you for the useful tips for expanding test applications. X-Plane 12 and DCS World will probably be included, but probably won’t be in the next test yet. The time complexity of the things we do (not only in the processor tests) is hitting a ceiling with the current editorial capabilities. Anyway, I’m putting both games on the list of “things that would be worthwhile to deal with as part of a methodology revision”.

  2. I would like a clarification on something.
    “The main role for the Ryzen 7 7800X3D is played by the same modification – the addition of a second piece of silicon on the CCD chiplet with the CPU cores”
    Is this line referring to the extra silicon for the 3D V-cache? Or the modification that only the other 2 7000 X3D chips have of a second CCD on the processor?

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