Temp directory size -2

I want to know the optimal size for temp directory (-2).

I’m planning on utilizing 8 parallel plotting and using 2TB + X TB.
X can be less than 2 TB, but at what size.

Staggering shall also be considered, but it becomes quite complicated.
Advises on finding X and optimal staggering time are much appreciated.

I know there are several other options:

  • raid those 2TB + X TB together if it exceeds total temp size I should be okay
  • use temp directory separately. may be 6 parallel plot for 2TB and 2 plots for 1TB
  • find optimal X