Stan_lmer really slow

[abs]

I have a very similar situation to OP.

I haven’t noticed much difference between brms with cmdstanr vs rstan, but I have found using threads=threading(2) tends to slow down my brm(y ~ a + b + c + (1|id), chains=4, cores=4) sampling by a factor of 2-3 on a 12-physical-core Ryzen.

@andrjohns

if you have a discrete GPU in your system you can use this to accelerate your models

Is this thread the best reference on using GPU parallelism?

@mike-lawrence

For something that simple yet with such large data, you probably want to use cmdstanr and write the model directly

What is the main difference between writing that model manually and using brms to generate one, such that manually writing it would make it perform faster?