- ReBarUEFI turns on a graphics speed feature called Resizable BAR on unsupported PCs.
- It gave one PC up to 12% more frames per second.
- You have to write a changed version of your motherboard's startup software yourself.
- A size the PC doesn't support can stop it from starting.
ReBarUEFI is a free tool that turns on a feature called Resizable BAR on PCs that don't officially support it. That feature can help a graphics card run faster. The project page says Intel's Arc graphics cards need it to work their best. A developer who goes by xCuri0 made it.
ReBarUEFI project page and guide
Your PC's startup software, often called the BIOS, has to be the kind called UEFI. You write a changed version of that software onto the motherboard yourself. The project's guide walks through each step.
The feature's size controls how much graphics memory the main chip can reach at once. An app from the project sets that size. The guide also says to switch on a BIOS option called 4G Decoding and switch off another one called CSM.
The developer says frames per second on their own PC went up by as much as 12%, with the size set to 2GB. That PC has an Intel i5 3470 chip and an RX 580 graphics card. The feature was also switched on in the card's driver. No game is named for that number.
For PCs whose startup software lacks support, the project says there's no known Windows workaround that avoids changing it. Linux is different. The project says recent Linux versions can turn the feature on by themselves once 4G Decoding is on. Some PCs need extra changes first.
An unsupported size can stop the PC from starting. The project says clearing the saved BIOS settings should turn the feature back off. Sometimes that means pulling the small battery off the motherboard. There's also a page of common problems and fixes for after the feature is on.
Not every card works with this tool. Owners of NVIDIA's 20 and 16 series cards get pointed to a separate project called NvStrapsReBar.
