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FYI: Resizable BAR (Base Address Register) is a PCI Express feature that removes the traditional 256MB memory limit, allowing your CPU to access your graphics card's entire VRAM at once for a potential 5% to 15% boost in gaming performance

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Thanks for the quick explanation. I'd been reading through the README to figure out what it was for, but wasn't able to.

Thanks, that context was definitely missing. Is that a feature that exists on any GPU brand/model?

Only on specific devices, but generally every GPU released in last few generations, and every dedicated GPU from intel[1], supports "large BAR" this way to map entire GPU memory into MMIO space. This has to be supported on both target device and AFAIK the PCI Root Port[2], and of course needs to be properly handled in firmware - which this tool fixes.

[1] Intel GPUs actually can't work without it, because they do not have legacy "windowing" mode where portions of 256MB BAR window are mapped to different areas in GPU memory

[2] This tool implies that it's possible to handle root port side entirely in firmware, but it's new to me at least, so I can't vouch for that :)

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