BAR1 went from 256 MiB to 16 GiB on an RTX 3080 and to 8 GiB on an RTX 3070 without the NVIDIA driver parameter the tweak guides recommend. On a third machine, an RTX 3090 on an Intel board, that same parameter was what stood between 256 MiB and 32 GiB, until a board firmware option did the same job without it.