Intel Core i5-13400F: Best price/perf ratio, questionable for games

Methodology: how we measure power draw

Thanks to the addition of E cores even in the lowest Core i5 Raptor Lake models (13400F and 13400), the raw performance between generations has advanced the most in years. However, the improvement may not always happen, the relatively small number of performance ones (P) combined with the lower Turbo Boost 2.0 clock speeds some games don’t like, and when they reach for E cores, the concept of big.LITTLE is at once detrimental.

Methodology: how we measure power draw

Measuring CPU power consumption is relatively simple, much easier than with graphics cards. All power goes through one or two EPS cables. We also use two to increase the cross-section, which is suitable for high performance AMD processors up to sTR(X)4 or for Intel HEDT, and in fact almost for mainstream processors as well. We have Prova 15 current probes to measure current directly on the wires. This is a much more accurate and reliable way of measuring than relying on internal sensors.

The only limitation of our current probes may be when testing the most powerful processors. These already exceed the maximum range of 30 A, at which high accuracy is guaranteed. For most processors, the range is optimal (even for measuring a lower load, when the probes can be switched to a lower and more accurate range of 4 A), but we will test models with power consumption over 360 W on our own device, a prototype of which we have already built. Its measuring range will no longer be limiting, but for the time being we will be using the Prova probes in the near future.

The probes are properly set to zero and connected to a UNI-T UT71E multimeter before each measurement. It records samples of current values during the tests via the IR-USB interface and writes them in a table at one-second intervals. We can then create bar graphs with power consumption patterns. But we always write average values in bar graphs. Measurements take place in various load modes. The lowest represents an idle Windows 10 desktop. This measurement takes place on a system that had been idle for quite some time.

   

Audio encoding (FLAC) represents a higher load, but processors use only one core or one thread for this. Higher loads, where more cores are involved, are games. We test power consumption in F1 2020, Shadow of the Tomb Raider and Total War Saga: Troy in 1920 × 1080 px. In this resolution, the power consumption is usually the highest or at least similar to that in lower or higher resolutions, where in most cases the CPU power draw rather decreases due to its lower utilization.

Like most motherboard manufacturers, we too ignore the time limit for “Tau”, after which the power consumption is to be reduced from the PL2 boost limit (when it exceeds the TDP) to the TDP/PL1 value, recommended by Intel, in our tests. This means that neither the power draw nor the clock speed after 56 seconds of higher load does not decrease and the performance is kept stable with just small fluctuations. We had been considering whether or not to respect the Tau. In the end, we decided not to because the vast majority of users won’t either, and therefore the results and comparisons would be relatively uninteresting. The solution would be to test with and without a power limit, but this is no longer possible due to time requirements.

We will pay more attention to the behavior of PL2 in motherboard tests, where it makes more sense. We always use motherboards with extremely robust, efficient VRM, so that the losses on MOSFETs distort the measured results as little as possible and the test setups are powered by a high-end 1200 W BeQuiet! Dark Power Pro 12 power supply. It is strong enough to supply every processor, even with a fully loaded GeForce RTX 3080, and at the same time achieves above-standard efficiency even at lower load. For a complete overview of test setup components, see Chapter 5 of this article.


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Comments (3) Add comment

  1. I wonder how the gaming results, especially power consumption, would look with E-cores turned off. Also, whether the Raptor Lake stepping has any performance advantage over Alder Lake one.

    1. After all, it seems that it might not be so easy to get Ci5-13400F in stepping B0. Big domestic shops (on the Czech-Slovak market) have only stepping C0 available, but we believe that sooner or later at least one piece will appear for testing. The availability of the variant based on Raptor Cove will probably be very low.

      When we were looking for Ci5-12400 stepping H0 last year, they were also in the minority, but there were still some, about in 40/60 ratio (H0/C0). It’s worse over here, and Intel is obviously trying to use as many B0 “silicon” as possible for more powerful processors.

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