- pv_n_tile = min(head_dim, 256) — MMA instruction N limit - n_pv_tiles = head_dim // pv_n_tile — outer loop count - V FMHA layout uses pv_n_tile (not head_dim) for N-tile slicing - Test loops over N-tiles at Python level, kernel processes (128, pv_n_tile) - For hd=512: 2 kernel launches with V[:,0:256] and V[:,256:512]