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)
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  • Xyler94 - Monday, February 10, 2020 - link

    Intel still wins in AVX512 and AI VNNI loads. AMD's got the brute force crown, which brute forcing your way through everything is still great, but if your workload uses 90% AVX512 or AI with VNNI, Intel would be more suited.

    But that's the great thing about competition, we now have choices, and it's no longer "Just get Intel".
  • Spunjji - Wednesday, February 12, 2020 - link

    A GPU or NPU would be even more suited to those workloads, though. AVX-512 is a weird middle-ground.
  • yetanotherhuman - Monday, February 10, 2020 - link

    I don't follow. It's not a gaming processor. It is, however, the fastest workstation/HEDT chip that exists. That's clearly not useless.
  • Spunjji - Monday, February 10, 2020 - link

    Another useless comment from timcarp.

    A moderator, a moderator, my kingdom for a moderator...
  • babadivad - Tuesday, February 11, 2020 - link

    How can you read this and not come away wih the knowledge that this is the most powerful CPU on the planet?
  • kardonn - Tuesday, February 11, 2020 - link

    I pre-ordered it, easiest hardware purchase decision of my life. My current fleet of workstations are dual 18C Xeons, they're done very well for me over the last 5-6 years but single core performance is a big deal in workstations...the 3990X really outshines the Xeons on those tasks, and then when it comes to multithreaded tasks it's just an absolute bloodbath.

    I have never owned AMD hardware in my life before this because Intel was always the best decision to buy if you need raw CPU power the way I do. Now AMD is king though, and I'm no fanboi or brand loyalist...I buy whatever is best.

    There's a reason AMD has been picking up a lot of server market share and workstation market share. They're making the CPUs that everyone wants right now.
  • spicemuthaf - Sunday, June 14, 2020 - link

    My friend,everything is useless if you don't know what to do with it
  • edsib1 - Friday, February 7, 2020 - link

    If you're going to run server benchmarks - especially with >32 cores, then use Linux/Unix. What self respecting mission critical business runs on windows server?
  • bloinkXP - Friday, February 7, 2020 - link

    That's not really an accurate statement. I work for one of the largest insurance companies in the world and we are 99% Windows. The days of Linux having more stability than Windows are long since over. As a matter of fact due to various compliance reporting we have to reboot all servers monthly (for patching) so even the famous "uptime" metric is largely useless. Our Windows platforms are very stable and handle the applications that our business requires (SQL Server/SP/.NET...etc)
  • vanilla_gorilla - Friday, February 7, 2020 - link

    > The days of Linux having more stability than Windows are long since over.


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