Any suggested gaussian grid numbers for the C768 grid

Are there any suggested grid numbers for the 12 km C768 grids, instead of outputting the default 384x190?

I mean suggested gaussian grid numbers, by default they are 384x190. In the case of high-resolution simulations, outputting results at the default 384x190 won't be as informative as it can be. 

Thanks in advance!

What is the recommended number of writing groups and tasks per group as opposed to the number of computation cores. My simulation stopped with the error message of "Operating system error: Cannot allocate memory/n Allocation would exceed memory limit". 

Thanks in advance!

Here is one example setting for C768 we use on NOAA hera:

PE_MEMBER01:             1728

write_groups:            3

write_tasks_per_group:   64