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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dwade123 - Friday, February 7, 2020 - link
Fact is most x399 owners can't afford the new TR. Only ones defending these shady prices are lowly AM4 users who love the brand to death. Therefore, overpriced.Makaveli - Friday, February 7, 2020 - link
lol the same X399 owners that were buying $500 motherboards?Can't afford this?
Do you even know what you are talking about?
dwade123 - Friday, February 7, 2020 - link
Another AM4 pleb trying to present X399 users. Most sold TR models were under $1k. TR 3000 series starts at $1500. Try again at shilling.Korguz - Friday, February 7, 2020 - link
dwade123 , sounds like you are happy paying intel for its cpus before Zen was released :-) the tables have turned and amd has the better cpus, and all of a sudden, its wrong to charge prices like this ??deksman2 - Friday, February 7, 2020 - link
This threadripper isn't necessarily targeted at mainstream consumers but rather small businesses and studios for content creation (such as VFX companies) - just like now, VFX companies went for 32 cores TR (most 'regular consumers' went for maybe 16 core/32 threads if they could afford it).And on that note... just who from the regular consumer market is able to afford $20,000 Xeon to begin with?
The Xeon's are 5x more expensive in comparison.
So, on a cost scale alone, which CPU do you think would be more accessible?
The Xeon's or 3990x?
Also, as the article points out, the software is having problems with scaling beyond 32 cores properly to begin with.
So, most 'regular consumers' who can afford TR will likely go for the 32 core/64 thread version from the Zen 2 family (whereas VFX companies and small businesses would transition to 3990x once the software catches up).
MattZN - Friday, February 7, 2020 - link
Shady prices? Buying a system with similar capabilities just 2 years ago would have cost me $40,000.-Matt
Spunjji - Monday, February 10, 2020 - link
dwade123 is a Trump supporter; logic has no place in its world view.Korguz - Saturday, February 8, 2020 - link
ahh so how about those that were defending intels prices before zen came out ?? going by what you said, those cpus were also overpriced ??? fact is, most couldnt afford the prices intel was charging for its higher end chips... its funny how it seems when intel does something its ok.. but when amd does the same, its wrong....MattZN - Friday, February 7, 2020 - link
I think you are taking a rather expansive license with your use of "most". A better way to think about it is... who actually *needs* a system this big? I would guess that most of the people you are thinking about don't actually need a 3990X system for what they do. Not really.Not to mention that actually utilizing a 64-core/128-thread CPU fully would also require commensurate amounts of ram. For our needs, which are mostly bulk-compiles, 2GB/thread is required which is $1400 worth of memory just by itself (for 256GB worth of EUDIMMs).
$4000 + $1400 + storage... yah, it adds up. At that point nobody is going to be crying over a $500 motherboard.
-Matt
Spunjji - Monday, February 10, 2020 - link
Ableist slurs scattered amidst a nonsensical rant?Check.
Strawmanning anyone who disagrees?
Check.
Referring to anyone not buying top-of-the-range gear as a "peasant"?
Check.
Oh boy, it's a troll! Hooray! :|