Intel Makes Resizable BAR Support Mandatory to Get the Most Performance Out of Arc GPUs
Intel‘s Arc A-Series of discrete GPUs is finally shaping up to be what the company had hoped for. With both mobile and desktop SKUs out right now, Arc is (technically) here at last. Given the infancy of Intel’s new GPU family, there are still lots of things that need to be sorted out including the entirety of the software suite.
Drivers are crucial in making a GPU perform as well as it can. Historically, neither NVIDIA nor AMD have ever been particularly great at drivers with both companies following more of a brute force approach to software. Many driver updates have caused more harm than benefit for the end user, which is quickly rectified by the manufacturer as soon as possible.
So, if two established players can’t get software right all the time and on first go, imagine Intel’s predicament. That being said, the company is slowly moving in the right direction, updating everything in its way to bolster Arc GPUs and brace them for public use. Today, the company has added an interesting nuance to all of that.
Resizable BAR Support
Intel has just published a new “Quick Start Guide” for its Arc desktop GPUs which include System Requirements necessary for optimal performance. The documents lists “Resizable BAR” as a must; mandatory for all Arc GPUs across all applications. It wasn’t made clear if Arc GPUs can work without Resizable BAR CPUs/motherboards at all.
As a quick reminder, Resizable BAR enables your CPU to have access to the entire GPU frame buffer at once. This allows any asset requests to be attended to more instantaneously and also simultaneously. Otherwise, the GPU’s memory has to constantly ask for and transfer assets between the CPU and GPU which is not ideal for today’s games that have massive-sized assets.
In simple words, it allows for quicker and more efficient asset management in games.
Re-BAR can be enabled in the motherboard’s BIOS with a simple toggle. The only caveat is that your motherboard chipset, CPU, and GPU all have to support it in order for it to work as best as possible. If there’s no motherboard or CPU support, and the GPU alone supports it, then it cannot utilize the power of Resizable BAR.
Continuing in that spirit, the guide confirms that Arc GPUs will only work with three Intel CPU generations and their subsequent motherboard chipsets as these support Re-BAR. These include the latest 12th Gen Core series with 600-series motherboards, and 11th & 10th Gen Core series which are compatible with 500 and 400-series motherboards.
Intel did not mention support for AMD processors but obviously Arc GPUs will work with those as well. This is further hinted at by a little footnote at the bottom reading “Additional platforms/motherboards with Smart Access Memory” will also work with Arc GPUs. Smart Access Memory is AMD’s term for Resizable BAR, which means AMD processors are unofficially supported.
While Resizable BAR support is a given in any new GPU, CPU, or motherboard coming out in 2022, and it does actually help improve performance, it’s still not available widely. NVIDIA only allows Resizable BAR support on its current-gen RTX 30 series GPUs while AMD is a little nicer with RX 6000 and RX 5000 series, both support Re-BAR.
That means a lot of people still do not have access to this technology depending on what components they have. So, if you buy an Arc GPU with a CPU or motherboard that lacks Re-BAR support, you’re locked out of using that Intel graphics card.
This is an interesting decision by Intel that reviewers should surely go over when testing this product. Arc desktop GPUs will be the very first GPU lineup to make Resizable BAR support a necessity instead of an option. Whether this actually results in better real-world performance remains yet to be seen.