Unless you compile multi-gigabyte targets, all writes will likely fit in a ram cache and thus cannot be a real bottleneck. That is assuming your compiler farm can read and compile at GB/s level, which is pretty unrealistic.

To test that, one can try it with ramdisk first, before getting an expensive ssd.

And that is something else that is alien to laptops. Best laptop I could find (for when I am away from my desktop) is 8c16t, that makes a massive difference for compilation.