
AMD Threadripper 3990X's 64 cores promise monster rendering - tambourine_man
https://www.cnet.com/news/amd-threadripper-3990x-64-cores-promise-monster-rendering/
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pella
[https://news.ycombinator.com/item?id=21628149](https://news.ycombinator.com/item?id=21628149)

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c2h5oh
That's about 3960X and 3970X, which are the 24 and 32 core CPUs that had their
benchmarks released today.

Post is about a 64 core part that launches next year.

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jowdones
Core count is becoming more and more bullshit. If I get performance X using 1
core and Y using all cores, then true core count is Y / X, regardless of what
advertised CPU count the manufacturer may dream.

Geekbench scores: \-----------------

Intel Core i7-8086K: 6288 single core, 29927 multicore, asvertised cores: 6,
real cores: 4.75, bullshit factor (advertised/real): 125%. Decent.

AMD Ryzen Threadripper 3970X: 5838 single core, 68457 multicore, advertised
cores: 32, real cores: 11.7, bullshit factor: 270%. Ridiculous.

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chapplap
This just means Geekbench isn't good at scaling to multiple cores. It could be
the workload or the implementation. If you have the right workload and a good
implementation, modern processors do scale reasonably well (all numbers with
Threadripper 3970X):

Cinebench R15: 206 single, 7302 multi, 35.4x scaling

POV-Ray: 9:02 single, 0:19 multi, 28.5x scaling

The scaling can be greater than the number of physical cores due to SMT. On
the other hand, turbo clocks increases the single-core speed by 10% or more on
most CPUs.

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eatmyshorts
Or they demonstrate that the CPU is throttling cores due to excessive heat.
Compare the 24-core 3960x to the 32-core 3970x, and also look at the power
consumed when running cores at 100% utilization. It would appear that the
3970x starts throttling the cores once ~21-22 cores are in full utilization,
leading the 3970x to be only marginally faster than the 3960x, even though it
has 50% more cores. EDIT: 3970x has a GeekBench score of 70655 (single-
threaded: 5684) while 3960x has a score of 66676 (single-threaded: 5703;
according to [https://www.anandtech.com/show/15044/the-amd-ryzen-
threadrip...](https://www.anandtech.com/show/15044/the-amd-ryzen-
threadripper-3960x-and-3970x-review-24-and-32-cores-on-7nm/8)). Meanwhile,
power consumption per core starts dropping off significantly at 21 cores for
both ([https://www.anandtech.com/show/15044/the-amd-ryzen-
threadrip...](https://www.anandtech.com/show/15044/the-amd-ryzen-
threadripper-3960x-and-3970x-review-24-and-32-cores-on-7nm/2))

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lliamander
> Meanwhile, power consumption per core starts dropping off significantly at
> 21 cores for both

Which you would expect with so many cores. Power consumption per core is
probably going to be even lower for the 3990X, especially considering it has
the same TDP.

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bloody-crow
This whole article is basically "there's a rumor 3990X will have 64 cores,
come out in 2020 and based on the performance of 39{6,7}0X is gonna be great
for rendering".

Maybe this will save someone a click.

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rubbingalcohol
Well it's not a rumor anymore, AMD announced it.

