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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ZoZo - Friday, February 7, 2020 - link
If not for Intel, they would probably also cost at least $1000. It takes 2 for competition.eva02langley - Friday, February 7, 2020 - link
Once again software developers are late to the game. MS really needs to upper their game with their OS division because one day, they will lose that monopoly for good. If it was not for the gaming industry, Windows would probably not be where it is today.extide - Friday, February 7, 2020 - link
I mean you can clearly see that Windows supports it just fine -- you just have to go for the Workstation/Enterprise version. It's not like Windows itself is totally behind the times.Kevin G - Friday, February 7, 2020 - link
The hard work is indeed done but not configured for the more mundane version of Windows where this certainly fits into the established licensing models: this is a single socket system and NUMA is not necessary here. A simple patch would fix things here.Then again as this article points out, MS didn't fix that a Xeon Phi 72xx with up 288 threads would appear as a five socket system. I would imagine that such a workstation too would have benefited from applications recognizing that it could have a single NUMA node (this was configurable in hardware).
drothgery - Friday, February 7, 2020 - link
And some quick googling shows Win 10 Pro Worksation is less than 10% of the cost of this CPU alone, so it's not like it'd be a big deal to anyone who actually bought one.Thanny - Saturday, February 8, 2020 - link
The Windows kernel is still badly broken when it comes to complicated NUMA scheduling. That's why the 2970WX, 2990WX, and all first-gen EPYC chips (with four dies) perform relatively badly under Windows, but quite well under Linux.The 64-thread limitation is quite mild compared to that problem.
FunBunny2 - Friday, February 7, 2020 - link
"If it was not for the gaming industry, Windows would probably not be where it is today."not in corporate, it's Office.
Makaveli - Friday, February 7, 2020 - link
Was just going to post this. I know everyone is all over Gaming and RGB. however that means nothing in the enterprise market.Microsoft get more revenue from office alone than probably the whole Xbox division and anything they get on the PC gaming side.
duvjones - Friday, February 7, 2020 - link
To be fair, a chip like this is not something that Mircosoft could predict coming in the x64 space. Which is what it giving Linux (and really any POSIX system) it's advantage, this kind of power and core count use to be reserved for the academic corners of high-end computing about 15-20 years ago.... Where Windows simply doesn't apply.They manage now, but... Mircosoft's is only making do with a workaround. They will have to address it at some point, the question is when.
Whiteknight2020 - Friday, February 7, 2020 - link
Yeah, because Windows server only supports 64 sockets and unlimited cores.....