Resizable BAR is a PCI Express protocol feature that allows the CPU to directly access all video card memory (VRAM) without constantly accessing small parts (256MB). The goal is clearly to speed up the entire data access process and achieve greater gaming performance (the amount often depends on the game and can be affected by the resolution, but on average we can talk about a 5-10%).
All video cards released before the RTX 3060 require a firmware update for the technology, introduced by AMD with the Ryzen 5000 and Radeon RX 6000 GPUs under the name of Smart Access Memory (SAM), to work.
The US company had promised that the new firmware would be arrived at the end of March, both for the Founders Editions and for the custom proposals of the partners and in fact, in these hours, we register starting the upgrade process to bring Resizable BAR to cards already deployed.
The update of the vBIOS (video BIOS) is something that enthusiasts or geeks (overclockers) usually do, while it is a much less common practice for the rest of PC users, who instead likely – at least once in their life – will have updated the Motherboard BIOS, both to correct malfunctions and to support new CPUs.
the start of the distribution of the update for your own models starting from tomorrow 30 April, while Galax e Gainward Cina have already published the new firmware dedicated to RTX 3060 Ti, 3070, 3080 and 3090 specifications dedicated to the local market.
⚠ BIOS Alert ⚠— EVGA UK (@TEAMEVGAUK) March 25, 2021
In addition to Z590, Z490, X299 and Z390, Z370 motherboards are now also ready for Resizable BAR.
The Resizable BAR update will be released on 03/30 for all GeForce RTX 30 series graphics cards.
More at: https://t.co/FBmrIIn3t6 pic.twitter.com/0qCLU9ogzx
From the first information released by those who managed to update their card, it does not seem that the tools install a real new BIOS, but instead apply simple changes to the existing firmware to unlock Resizable BAR.
Asus, MSI, Gigabyte and the rest of the Nvidia partners will follow suit, so we suggest you wait for the appearance of dedicated tools and / or vBIOS on the page dedicated to the specific model in your possession. Once available, download the package and follow the on-screen instructions: be careful not to interrupt the update process while it is running, you could irreparably damage the video card (at your own risk!).
In addition to the video card, update your motherboard’s BIOS, always starting from the dedicated page on the manufacturer’s website. In the case of AMD, you need a platform with a 400 – 500 series chipset and a Ryzen 5000 CPU, while in Intel’s a 10th or 11th generation Core CPU on motherboards with PCH 400 and 500. Then you just need to update the latest version graphics drivers e activate the functionality from the motherboard BIOS, usually located in the PCI section: enable “Above 4G decoding” and any other item that appears (leaving it on Auto or Enabled, it depends on the motherboard).
To verify that everything went well, you have two options: check from the Nvidia control panel, via System Information, the presence of a “Yes” on the Resizable BAR line or download and install the latest version of GPU-Z (as shown in the screenshot above).
AMD recently announced the support also extended to Ryzen 3000 CPUs (except for the G models) on the 500 series platforms, but we do not know at the moment if the compatibility affects only the Radeon RX 6000 or also includes the GeForce RTX 3000; otherwise you will have to be patient a little longer.