Don’t worry: this is good news for a change! If you’ve got an Nvidia GPU, then you’ll want to look at upgrading your drivers today, because the fancy new RTX cards just got a shiny new feature.
After months of AMD crowing about their resizable BAR, or Smart Access Memory, Nvidia has finally added support for the PCI Express technology into their own Geforce RTX GPUs.
The GTX 3060 (if you could afford the absurd gouging) was the first RTX card to ship with support for resizable BAR, but as of Wednesday morning Australian time Nvidia has extended support for the technology to all of its 3000-series RTX GPUs. It’s not just desktop GPUs either: those rocking RTX 3000 series GPUs in gaming laptops will benefit from this as well.
If you’re out of the loop, resizable BAR support — or Smart Access Memory for AMD users — is basically a technology in the PCI Express 4.0 specification that can give the CPU direct access to all of the memory on your graphics card. Traditionally, CPUs can only access a maximum of 256MB of the GPU’s memory, so theoretically there could be a potential performance boost.
In practice, a lot of games don’t get anything from Smart Access Memory/resizable BAR just yet. There are some select titles where it makes a massive difference — Forza Horizon 4 probably being the best example, which showcased a 13 to 18 per cent jump at all resolutions on the RX 6800. (But Total War: Three Kingdoms showcased no meaningful performance gains, and Shadow of the Tomb Raider was marginal at best.)
Naturally, not all motherboards, CPUs and laptops will support this just yet. Because it’s part of the PCIe 4.0 spec, you’ll need a PCIe 4.0 capable system. For those on desktop PCs, this is the list of configurations that will support resizable BAR for Nvidia cards:
If you have a suitable Intel/AMD/motherboard combo that fits the list, and you want to enable resizable BAR, you’ll have to go through a few steps. This will require jumping into your computer’s BIOS menu, so if you haven’t done that before, Paul’s Hardware has a good video.
But once you know how to do that, follow these steps:
- Confirm you have a compatible CPU & CPU chipset
- Confirm you have a compatible motherboard
- Update your motherboard’s BIOS, if required, by installing an update from the manufacturer. Then enable Resizable BAR support in your motherboard’s BIOS interface.
- Update to the latest GeForce Game Ready Driver (version 465.89 WHQL at the time of writing, released March 30th, 2021), or a later version
- If you have a GeForce RTX 3060, you’re good to go. If you have a GeForce RTX 3060 Ti, 3070, 3080, or 3090, then you may require an updated VBIOS
- If you have a Founders Edition graphics card from NVIDIA, get your VBIOS update tool directly from our website. If you have a custom partner card, get the update tool from their site
- Verify Resizable BAR is enabled in the NVIDIA Control Panel
Once that’s done, then it’s onto the games! These are the titles that support resizable BAR right now — which is to say, these are the games Nvidia says you’ll actually see resizable BAR make some kind of impact on:
- Assassin’s Creed Valhalla
- Battlefield V
- Borderlands 3
- Cyberpunk 2077
- Death Stranding
- DIRT 5
- F1 2020
- Forza Horizon 4
- Gears 5
- Hitman 2
- Hitman 3
- Horizon Zero Dawn
- Metro Exodus
- Red Dead Redemption 2
- Watch Dogs Legion
Update: As called out by [email protected]! below, Nvidia is taking a different approach to AMD with Resizable BAR. Rather than just enabling or disabling system wide, Nvidia will use its Game Ready drivers to enable the feature on a game-by-game basis:
In practice, the performance benefits of Resizable BAR can vary substantially from game to game. In our testing, we’ve found some titles benefit from a few percent, up to 12%. However, there are also titles that see a decrease in performance, so NVIDIA will be pre-testing titles and using game profiles to enable Resizable BAR only when it has a positive performance impact. That way you won’t have to worry about bugs or performance decreases, and won’t have to rely on the community to benchmark each title and discover whether Resizable BAR is beneficial in the games you’re playing.
So, a pretty decent list to kick off with. Given AMD and Nvidia both support resizable BAR, the list of games should expand pretty quickly over time. For more info on how to get the necessary BIOS update for your system, as well as the firmware updates for Founders Edition cards and third-party RTX models, head to the Nvidia landing page here.