Intel Arc Alchemist GPUs To Get Resizable BAR Support on Linux Platforms


Back in 2020, Resizable BAR was all the buzz with both AMD & NVIDIA enabling support for the feature on their graphics cards but now, Intel has also confirmed to be adding support for the technology on their upcoming Arc Alchemist GPUs.

Intel Arc Alchemist GPUs Will Be Getting Resizable BAR Support on Linux

In a report by Phoronix, the latest Linux graphics kernel has mentioned ' Resizable BAR' or ReBAR support within the patches. The latest patches include a small BAR recovery support for the Intel's Kernel graphics driver on the Linuxx platform. Following is what the patch states:

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Starting from DG2 we will have resizable BAR support for device local-memory, but in some cases the final BAR size might still be smaller than the total local-memory size. In such cases only part of local-memory will be CPU accessible, while the remainder is only accessible via the GPU. This series adds the basic enablers needed to ensure that the entire local-memory range is usable.

via Phoronix

Considering the patch was sent out for Linux 5.17, it is likely that we can see the Resizable BAR supprort being added as early as Linux 5.18. So if users wan't to utilize ReBAR with Intel's GPUs within the Linux ecosystem, they would have to upgrad to the latest Linux and MESA build. Intel already offers Resizable BAR support on its desktop platforms starting the 300-series lineup and considering that other GPU makers are offering the tech on both desktops and laptops, it is likely that Intel would also follow the same route with its Arc Alchemist GPU lineup.

ReBAR essentially defines how much discrete GPU memory space can be mapped and today's PCs are typically limited to 256 MB of mapped memory. With BAR, the system can access all of the GPU memory, removing any bottlenecks to allow for faster performance. So far, BAR has shown mixed performance numbers with gains in some titles and no performance benefits in others. There are also a few cases where the system produces lower performance with BAR enabled but that's just a small portion so having it enabled isn't a bad idea and it's great to see Intel also working towards making such features open-source.