Frequency, Temperature, and Power

A lot of questions will be asked about the frequency, temperature, and power of this chip: splitting 280W across all the cores might result in a low all-core frequency and require a super high current draw, or given recent reports of AMD CPUs not meeting their rated turbo frequencies. We wanted to put our data right here in the front half of the review to address this straight away.

We kept this test simple – we used our new NAMD benchmark, a molecular dynamics compute solver, which is an example workload for a system with this many cores. It’s a heavy all-core load that continually cycles around the ApoA1 test simulating as many picoseconds of molecular movement as possible. We run a frequency and thermal logger, left the system idle for 30 seconds to reach an idle steady state, and then fired up the benchmark until a steady state was reached.

For the frequencies we saw an ‘idle’ of ~3600 MHz, which then spiked to 4167 MHz when the test began, and average 3463 MHz across all cores over the first 6 minutes or so of the test. We saw a frequency low point of 2935 MHz, however in this context it’s the average that matters.

For thermals on the same benchmark, using our Thermaltake Riing 360 closed loop liquid cooler, we saw 35ºC reported on the CPU at idle, which rose to 64ºC after 90 seconds or so, and a steady state after five minutes at 68ºC. This is an ideal scenario, due to the system being on an open test bed, but the thing to note here is that despite the high overall power of the CPU, the power per core is not that high.


Click to zoom

This is our usual test suite for per-core power, however I’ve condensed it horizontally as having all 64 cores is a bit much. At the low loads, we’re seeing the first few cores take 8-10W of power each, for 4.35 GHz, however at the other end of the scale, the CPUs are barely touching 3.0 W each, for 3.45 GHz. At this end of the spectrum, we’re definitely seeing AMD’s Zen 2 cores perform at a very efficient point, and that’s even without all 280 W, given that around 80-90W is required for the chipset and inter-chip infinity fabric: all 64 cores, running at almost 3.5 GHz, for around 200W. From this data, we need at least 20 cores active in order to hit the full 280W of the processor.

We can compare these values to other AMD Threadripper processors, as well as the high-end Ryzens:

AMD Power/Frequency Comparison
AnandTech Cores CPU TDP   1-Core
Power
1-Core
Freq
Full Load
Power/core
Full Load
Freq
3990X 64 280 W   10.4 W 4350 3.0 W 3450
3970X 32 280 W   13.0 W 4310 7.0 W 3810
3960X 24 280 W   13.5 W 4400 8.6 W 3950
3950X 16 105 W   18.3 W 4450 7.1 W 3885

The 3990X exhibits a much lower power-per-core value than any of the other CPUs, which means a lower per-core frequency, but it isn’t all that far off at all: less than half the power for only 400 MHz less. This is where the real efficiency of these CPUs comes into play.

The 64 Core Threadripper 3990X CPU Review The Windows and Multithreading Problem (A Must Read)
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  • jmunjr - Friday, February 7, 2020 - link

    Wow I saw benchmarks of the 3990X vs 2 x Xeon Platinum 8280 on Linux and what a beat down. The 3990X at worst matched the 2x8280 on a few tests and soundly beat on many others. Impressive!
  • Batty - Friday, February 7, 2020 - link

    Several people suggested compiling source code would be a good test of this chip's performance. I agree, I would recommend Unreal Engine 4.24.1 built clean from source, it is a vast codebase and scales very well with more cores. My Intel 6/12 core machine takes 73 minutes, for instance.
  • MattZN - Friday, February 7, 2020 - link

    My personal favorite is chromium (i.e. the source base for the chrome web browser). 30,000+ C++ files is a great test.

    -Matt
  • Rudde - Monday, February 10, 2020 - link

    Anantech used to benchmark Chromium compile. I can't recall why they stopped.
  • Ian Cutress - Friday, February 14, 2020 - link

    Something in Windows 1903/1909 broke our script. Due to events and travel I haven't had a week of downtime to sit down and fix it.
  • wizyy - Friday, February 7, 2020 - link

    "In The Midst Of Chaos, AMD Seeks Opportunity"

    Sounds like a title of one of the chapters of Romance of the Three Kingdoms (Novel by Luo Guanzhong, XIV century).
    Even if it isn't meant like so, it's appreciated :)
  • Ian Cutress - Friday, February 14, 2020 - link

    It's an edited Sun Tzu quote :)
  • 007ELmO - Friday, February 7, 2020 - link

    When you use the word "amortize" with anything but a mortgage.
  • deksman2 - Friday, February 7, 2020 - link

    You know, I actually find that this is quite intuitive review of the CPU which illustrates how badly Windows software is lagging behind hw.

    And while Linux may not be the go to choice for Enterprise users (although stability wise I do think Linux is pretty solid), I still think including it in this review would have been a good idea (as historically, it DOES have FAR superior support for multi-core CPU's above 32 cores than Windows).

    On that note, perhaps Enterprise users should consider going Linux and looking for open source software to replace their existing ones.
    Open source generally can get better upgrades/support for the simple reason its open.

    I've seen businesses using Linux (where commonly before they had Windows) and using exactly the same software for example.
    So, I don't think transitioning to Linux etc. would be a problem. In the short term with adjustment and all, yes perhaps, but in the long run, they will probably save money by using free/open source software. Even in the short term, companies could be running both Windows and Linux together to help with adjustment and training until they are ready to completely move to Linux.
  • eek2121 - Friday, February 7, 2020 - link

    Meanwhile, Linux unlocks the true potential of this beast: https://www.phoronix.com/scan.php?page=article&...

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