Best CPU for RStan/brms

Hi all, just a quick question about recommendations for CPU’s. I’m looking into building some new computers for my research lab and I’m having trouble finding benchmarks for CPU’s to help me decide. So far I’ve seen the Chromium Code Compile benchmark in Gamer’s Nexus reviews (e.g., AMD Ryzen 9 7900X3D CPU Review & Benchmarks: Spoiled by the 5800X3D - YouTube), and the Microsoft Visual Studio C++ benchmark on TechPowerUp (AMD Ryzen 9 7950X3D Review - Best of Both Worlds - Software & Game Development | TechPowerUp). Are either of these representative of R generally, or running brms models specifically?

Obviously I can’t go wrong by going as expensive as possible with the Ryzen 7950X3D. But I don’t feel like spending $800 on 16 cores when I’m only running 4-5 chains, and half as many cores will do fine. Wondering what the best balance is between price and performance.


There are some good posts (perhaps dated) here:

I think the consensus revolved around (1) high cache (i.e., L3) on the CPU, (2) moar cores, (3) RAM.

I’ve been impressed with the speedups from within-chain parallelization in brms, so even if you’re running 4 chains, additional cores help.


Thank you!!

The high cache thing is particularly interesting. After seeing that cache made no difference at all in the Chromium code compile benchmarks I thought it wouldn’t matter here either .I guess I should go for AMD’s latest round of X3D chips then.

I’d be very interested to see a benchmark comparison between the 7950X and the 7950X3D. The 3D cache feels like it could substantially improve Stan’s sampling speed.

And also one vs the 13900K, since it has the same number of threads but more physical cores.

Same. I’d also like to know how much of a role RAM speed and latency plays; in one Hardware Unboxed video I saw recently, having faster RAM (6000 MHz DDR5) gave between modest and substantial performance uplifts in gaming, depending on the game, for Ryzen 7000 chips.

Shame there’s no real benchmarks I can find anywhere. The suggestion just seems to be “get the fastest, most expensive thing with all the cores, most cache, and highest boost clocks.” Would love to know where the best performance per dollar ends up though…having a hard time justifying $800 for 7950X3D over the cheaper 7900X3D with no data.