keep in mind that movegroup 3 = <RUMr> -> branching factor of 12 at each new depth

so depth 8 prune tables are 12 times as large as depth 7

so for example if your computer has like 2 GB RAM free for HARCS and depth 7 tables are at 256 MB, depth 8 = 12 * 256 = 3 GB = rip