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
Full Load
Full Load
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)


View All Comments

  • FakThisShttyGame - Friday, February 7, 2020 - link

    Intel needs to get their shit together and be competitive again or else AMD will do the same Skylake 14nm+++++ BS to us in the future. We need competition Reply
  • Makaveli - Friday, February 7, 2020 - link

    AMD doesn't have a big enough market share yet and money to do what intel has done the last few years slow down. Reply
  • HellHammerThrash - Friday, February 7, 2020 - link

    I just hope this cpu will run both Zork and Pong well. Idk, maybe throw in a pair of Titan RTX's and enough RAM too.... Reply
  • 7beauties - Friday, February 7, 2020 - link

    Ian, why did you close with such a final thought? Your admitting to having made up the $3990 price tag as a joke makes me mistrust your reviews and thoughts. Reply
  • Ian Cutress - Saturday, February 8, 2020 - link

    What? AMD briefed us before the CES keynote about the performance and their intended price. I said they should make it $3990. About 4am the next morning before the keynote, I got an email saying that they'd changed the SEP to $3990. Reply
  • biodoc - Saturday, February 8, 2020 - link

    Linux unleashes the full power of this chip. Read the phoronix review.
  • dickeywang - Saturday, February 8, 2020 - link

    It would've be nice if we could see some benchmark on a Linux box. Reply
  • Ric1194 - Saturday, February 8, 2020 - link

    I think that the results are a bit misleading, power user are more about multitasking, where processor grouping is not that important, people who buy a threadripper-3990x will do a lot of things simultaneously like playing a game while downloading something and waiting for other things to finish,thus to represent a more realistic scenario it would be better to do tow or more simultaneous programs, like Photoshop and gaming while downloading something Reply
  • GreenReaper - Saturday, February 8, 2020 - link

    I think if you're switching between a variety of tasks, and playing games, you might prefer the higher-frequency, lower-core options - and perhaps some judicious prioritization.

    You have limited power budget. Unless you *really* know you need that many cores, and ideally have seen someone do a benchmark of it beforehand, you probably don't.
  • Zingam - Sunday, February 9, 2020 - link

    I would setup several machines if I need to do different things at the same time. Buying a single threadripper to multitask - is more than just stupid - it is also expensive. Reply

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