Chia 1.2.11 MadMax plotter Buckets - Use of Ram

I would need advice for buckets, in this latest version of chia with the possibility of plotting k33 with madmax, there is the possibility of setting p1 and p3 + p4 which are by default on 256,
how to properly configure these to have a maximum use of the ram instead of M.2,
I had the impression of using more the ram and less the M.2 in 128 …?
or configure P1 in 128 and P3 + P4 in 256? or the opposite? thanks for your advice
(have 32Mo for ram - 1 m.2 2To and 1 1To)