The 64 Core Threadripper 3990X CPU Review: In The Midst Of Chaos, AMD Seeks Opportunity
by Dr. Ian Cutress & Gavin Bonshor on February 7, 2020 9:00 AM ESTFrequency, 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.
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lipscomb88 - Sunday, February 9, 2020 - link
Ltt showed crysis running on a software renderer on a 3970x and a 3990x. Definitely a difference between those two chips but it still chugs at times. Really cool to see.At some point, a high cord count cpu mimics the parallelization in gpus well enough to render well.
Spunjji - Wednesday, February 12, 2020 - link
It's notable in that video that the vast majority of the cores flicker around 2-5% utilisation; it looks like there's still a significant bottleneck besides the sheer number of cores for processing.ZoZo - Friday, February 7, 2020 - link
Better grap this one before it is replaced by the 4990X at $4990.Irata - Friday, February 7, 2020 - link
Ian and Gavin: Thanks for the review and particularly the Windows version analysis.While I agree with your conclusions, I have a suggestion for future high core count CPU reviews:
How about trying to run several things at once, i.e. A game while the CPU is rendering, rendering while compiling....
Perhaps there are actual use cases that could apply where you run several demanding tasks at once that could not be done so far since the CPU power was not there.
Hulk - Friday, February 7, 2020 - link
I second this suggestion. One thing that annoys me with my 4770k is that if I'm rendering a video using Handbrake and trying to work on an audio project in Presonus Studio One there isn't enough compute for Studio One so it's all distortion. But realistically 12 cores would probably do this for me;)Irata - Friday, February 7, 2020 - link
I remember seeing one review for TR3 (the 32c version) that die a multi tasking stress test which was very interesting.Afair it was on Adoredtv but another reviewer did it.
DannyH246 - Friday, February 7, 2020 - link
Compiling was asked for in previous workstation class CPU reviews, and many people asked for it for AMD's 16 core Ryzen release....instead we get a gaming benchmark where they show Intel's 8 core CPU winning. What do you expect from IntelTech.com.Thanny - Saturday, February 8, 2020 - link
That used to be routine in the early days of multi-core CPU reviews.Seems these days everyone has forgotten about the concept of multitasking.
alpha754293 - Friday, February 7, 2020 - link
I'm currently in discussions/in the works of getting a system put together in order to replace my four-node micro-cluster with either one or two of these AMD 3rd gen Threadripper systems.The price-per-performance is too compelling of a story for me NOT to dump my entire micro-cluster now and switch over to this.
eastcoast_pete - Friday, February 7, 2020 - link
Thanks Ian and Gavin! While the business cases for this 64 core TR CPU are limited, video editing and software-based encoding are two of them. A lot of people don't realize that a lot of video is already shot in 8K 60p, and those RAW files are enormous and tax any CPU, even this beast. Also, some of these editing suites either already have patches available, and apparently one of two of them are from AMD. So, not the CPU for gaming, but it has a place for certain tasks.