pytc.solver.isdf_xtc_ccsd._pipelined_x_panel_size¶

pytc.solver.isdf_xtc_ccsd._pipelined_x_panel_size(nvir, rank, working_set_bytes, *, rank_panel_size, panel_budget_bytes=None)[source]¶

Rank width of one pipelined X panel, a multiple of rank_panel_size.

The per-panel budget is one third of the measured free device memory after the t2/accumulator working set and a 4 GiB reserve: resident panel, in-flight prefetch, and slack for kernel temporaries and BFC fragmentation. PYTC_X_PANEL_BUDGET_GB (read at call time) overrides the computed budget. When device memory is unmeasurable and no override is given, the width falls back to rank_panel_size.