If you have an older PC that does not officially support ReBAR, you might be interested in this new mod. An open source tool is now available to enable ReBAR on more systems, which can improve gaming performance by as much as 12 percent.
The ResizableBAR technology became popular in 2020 when AMD introduced Smart Access Memory (SAM). However, the capability has been available on many motherboards for over a decade, so it's no surprise that older systems also support the technology.
Image credit: xCuri0 (Github)
As explained by HKEPC (via PCGamer), the ReBarUEFI project replaces existing routines that verify ReBAR compliance with a boot-time module. During system startup, it modifies the ReBAR size and persuades the OS to enable it, resulting in improved performance. While this may not apply to all systems, information on activating it, including hidden 4G encoding capabilities, is available on the project's GitHub page.
With the mod, you can enable ReBAR on older systems, including those with Intel Sandy Bridge processors from 2011. Once activated, ReBAR can map more than 256MB of system memory to GPU memory, significantly improving game performance. The creator of this hack claims a 12% performance improvement on a Core i3-3470 CPU combined with a Radeon RX 580 GPU after activating 2GB of BAR size, but the average improvement is more modest, at around 6%. As with any modifications, we advise caution, especially when working with BIOSes.
Discuss on our Facebook page, HERE.
KitGuru says: Do you have an old system that could benefit from this mod? Do you plan to try, or would you rather avoid tinkering with your BIOS?