Highly anticipated: Nvidia finally began to provide Resizable BAR support, first of all desktop RTX 3060 and a few laptops equipped with RTX 3000 series. Enabling it may be a bit of a hassle, but this is a free upgrade, so it will be welcome.
The resizable BAR is a feature of the PCIe standard, which enables the system’s CPU to see all of the GPU memory subsystem, not just a small portion of 256 MB. To achieve this function, low-level support from the CPU, motherboard and GPU is required. This is the way AMD, which designed these three functions, took the lead in implementing the resizable BAR (called SAM).
In our test, enabling SAM on the RX 6800 can increase the average frame rate of the game by up to 20%, or increase the average frame rate of the game by up to 1
Understandably, Nvidia is taking another path. Their driver will disable “Resizable BAR” by default, and only turn it on in headlines where Nvidia has found it can improve performance. At the time of writing, these are eight headings:
- Assassin’s Creed Valhalla
- Battlefield 5
- Borderlands 3
- Forza Motorsport: Horizon 4
- Gear 5
- Metro Exodus
- Red Dead Redemption 2
- Watchdogs: Legion
Nvidia said that in these games, the resizable BAR can increase performance “from a few percent to ten percent.” In late March, when the remaining RTX 3000 series gain support for Resizable BAR, more games will be added to the list. Nvidia’s selective approach is undoubtedly a good idea (if done correctly), but unfortunately, the complexity of enabling Resizable BAR makes Nvidia’s advantage impossible.
In laptops, the situation is okay, but not ideal: some laptops will enable “resizable BAR”, some will not, and you can’t do anything about it. Nvidia stated that it “will contact each notebook manufacturer to find out whether a specific model supports Resizable BAR.”
Desktop compatibility is a 3D chess game. Enabling resizable BAR, or most likely finding that your system does not support it, is a five-step process. First, you need to check whether your CPU is compatible: all AMD 5000 series CPUs are the same as all 10th generation Intel processors, but only the upcoming 11th generation i5, i7 and i9 series will be compatible. . It’s simple…
Step 2: Check the chipset of the motherboard. AMD 500 series chipsets are compatible (if not currently popular), while 400 series chipsets are compatible on motherboards that are also compatible with Ryzen 5000 series CPUs. Intel’s 500-series chipsets announced at the time of writing are compatible, and their 400-series chipsets are also compatible. Are you still here?
The third step is more troublesome: you need to update the SBIOS of the motherboard, but you only want to have an update. According to Nvidia, “The following manufacturers are providing SBIOS updates for some motherboards to enable resizable BARs with GeForce RTX 30 series desktop graphics cards: Asus, Asrock, Colorful, EVGA, Gigabyte, and MSI.”
Fourth, you need to update the VBIOS of the GPU, unless you are one of the lucky ones to use the new RTX 3060. For Founder Edition Edition owners, Nvidia will provide updates on its own, but everyone else needs to download the GPU manufacturer page from it.
At home: Update your GPU driver. After that, you can check whether the “Resizable BAR” is working properly in the “Nvidia Control Panel” in the “System Information” tab.