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Comment by henrydark | Hacker News Reader

As per the piece, open 128 documents on a 128 core machine, and you'll see the difference.

How many people actually use a 128 core machine though? The absolute biggest AMD Threadripper you can get only has 64.

96 virtual cores is a popular choice on AWS, being cost effective in some industry scenarios. I'm certain the analysis of the piece applies

No one needs more than 64 cores?

> The absolute biggest AMD Threadripper you can get only has 64.

You can get a machine with dual 64-core AMD EPYC 7662 CPUs[0] for a total of 128 cores. It will cost you almost $20k, though—for the most basic configuration.

[0] https://bizon-tech.com/bizon-x6000.html#959:8714;960:4858;96...

Those Threadrippers have two vCPUs per core, so you can definitely have 128 things that appear to proceed in parallel.

A dual socket EPYC costs about 15K. You can rent some online for 400$ a month. This gives you 128 cores for a relatively low price.

That seems like an awfully short sighted argument. Less than 20 years ago we were all using single-core CPUs. Now most of us have at least 6 cores if not more in a battery powered handheld device that we don't even expect to do much compute work on (aka, smartphones). And 8-16 cores w/ SMT are not an unusual consumer laptop/desktop configuration.

The articles suggestion that it's only a matter of time for 128+ core CPUs to be common, at least in the server space, is probably the least contentious argument it makes?

128 cores is only 2x 64 cores, and 64 cores is a whopping 4x what AMD's top dog desktop CPU offers, so if you have to go this far for exceptions to be slow, then maybe they don't matter for most users.

Your math is a bit off, confusing threads & cores. 128 threads is only 4x of what AMD's top desktop CPU offers, and is what current AMD server CPUs offer in a single socket system. And over the past 20 years consumer CPUs have 32x'd their thread count. A 4x increase over the next 10+ years really doesn't seem all that far-fetched.

Also, the scaling problems show up far before 128 threads are used. The scaling issues start showing up at just 4-8 threads, depending on the error rate.

Also also, C++ is used in a hell of a lot more places than just consumer desktops. So the current limitations of consumer desktops is fully irrelevant anyway.

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