Power Consumption and TDP

The way AMD and Intel use the term Thermal Design Power (TDP) is different. Technically it is a measure of cooling ability needed for a given processor, which is how AMD use it, or the more common way is a measure of power consumption, how Intel does it. The question becomes whether it means sustained power, or turbo power - most people assume it's the latter, but Intel use it for the former (sustained) power. We describe this in detail in our article here:

https://www.anandtech.com/show/13544/why-intel-processors-draw-more-power-than-expected-tdp-turbo

There is also the added factor of the luck of the draw - two processors that have the same name can potentially vary wildly in power consumption. Both AMD and Intel apply 'binning' rules, such that CPUs that hit a minimum grade are stamped as that processor model. This means that a processor can either only just pass the grade, or be a super perfect chip, but still be sold as the same. There is also the possibility that the company could downgrade a higher model and rebadge it to the lower model in order to adjust inventory. This is something to keep in mind when looking at power numbers.

Power Consumption

Power consumption was tested on the system while in a single MSI GTX 1080 GPU configuration with a wall meter connected to a power supply with ~75% efficiency > 50W, and 90%+ efficiency at 250W, suitable for both idle and multi-GPU loading. Our method of power reading actually bypasses the power management of the UEFI and the board to supply components with power under load, instead using the readings that the system is directly be told from the CPU for managing fan speeds, temperatures, current protection, etc. This way of reading the power has positives and negatives, but provides a sustainable CPU-only comparison value.

In our test, we use affinity masking to test from 0 to double the threads of the CPU while running the POV-Ray benchmark, and reporting the peak power from around ~20 seconds into the test when all threads are loaded. The 'Full Load' value takes the peak value out of all the affinity mark sub-tests. POV-Ray uses up to AVX2 instructions, which can draw more power than non-AVX code.

Power (Package), Full Load

As expected, the 2500X consumes more power than the 2300X, but both are beaten by almost 10W by the Core i3-8350K, and the Core i5-8600K sits in between the two AMD chips. Perhaps suprisingly, our Ryzen 5 2500X sample consumes more power at load than our Ryzen 5 2600 chip, which is rated at the same TDP. It would appear that the 65W TDP of our Ryzen 5 2500X is set too low, or we just have a bad chip that is applying a lot of voltage. The winners in power here are the Ryzen APUs.

Gaming: F1 2018 AMD Ryzen 5 2500X and Ryzen 3 2300X Conclusion
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  • Korguz - Monday, February 11, 2019 - link

    Phynaz
    better then the typical Intel.. overpriced, and not much gained
    Reply
  • MDD1963 - Monday, February 11, 2019 - link

    How many folks with GTX1080s would be using either of these CPUs tested (even if they were for sale)? :) Reply
  • Allan_Hundeboll - Tuesday, February 12, 2019 - link

    Gamers on a budget Reply
  • mikato - Thursday, April 4, 2019 - link

    Someone that decided to start gaming, or changed to a game that required more graphics power so bought a graphics card. Maybe a kid whose parents bought a computer, or a hand-me-down computer. Even I have been gaming and building computers a long time and I have upgraded the graphics card on my computers several times around the middle of that system's lifetime (I keep them pretty long). I have friends that play WoW and needed to upgrade.There are plenty of situations.

    Have you seen gaming benchmarks with low end CPUs vs high end CPUs when both have the same high end graphics card?
    Reply
  • Ethnipod - Monday, February 11, 2019 - link

    wrong power consumption test ...

    Ryzen 5 2500X get DDR4 2933 (1.3 V) vs coffe lake DDR4 2667 (1.2 V).

    (for Ryzen 5 2500X clock up ram freq to 3200, or downclock to 2667)

    ty and sorry for my eng.
    Reply
  • pajuk - Monday, February 11, 2019 - link

    another intel biased review . Why didint youput the price of the i5-8600k like in other reviews??
    maybe because you know that it costs the same as amd 2700 ??? tired of LIARS.
    Reply
  • Korguz - Monday, February 11, 2019 - link

    prove it.. post some links... Reply
  • Irata - Tuesday, February 12, 2019 - link

    The statement by Pajuk is actually not correct - the i5-8600k costs $288.96 boxed, the Ryzen 7 2700 229.99 - both at Newegg - so it's not the same price but $60 more. Reply
  • pajuk - Tuesday, February 12, 2019 - link

    https://www.pcdiga.com/processador-amd-ryzen-7-270...
    https://www.pcdiga.com/processador-intel-core-i5-8...
    Reply
  • pajuk - Tuesday, February 12, 2019 - link

    you help me even more, this LIARS in anadtech are as bad as tomshardware. Reply

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