Resizable BAR – Geforce RTX 3080 mot Radeon RX 6800 XT

Earlier in March, Nvidia introduced support for the PCI Express technology Resizable BAR together with the Geforce RTX 3060 graphics card. Resizable BAR is the same technology used by AMD’s Smart Access Memory, which allows the processor to address the entire graphics card’s memory per call instead of the 256 MB which is usually exposed with the off feature – something that can potentially provide significantly higher game performance in selected titles.

► Resizable BAR with Geforce RTX 3060 for better gaming performance

Last week, Nvidia rolled out support for the technology along with the remaining Geforce RTX 3000 family of graphics cards, namely Geforce RTX 3090, Geforce RTX 3080, Geforce RTX 3070 and Geforce RTX 3060 Ti. To enable the support, at least driver version 465.89 is required along with a new BIOS for the current graphics card. Nvidia has gathered information and links to various partner manufacturers’ BIOS updates on this page.

On top of this, a motherboard platform is needed that supports Resizable BAR. Here, too, Nvidia has a landing page with information about which platforms support the technology. It should be mentioned, however, that several older platforms than those mentioned on Nvidia’s site have recently received support for the technology, and it is therefore best to look at the motherboard manufacturer’s website to see if a new BIOS has been released for your own motherboard.

Components of the test system

In this article, we thought we’d take a closer look at the performance gains that can be extracted from the popular Geforce RTX 3080 model when Resizable BAR is activated. As a reference, we have AMD’s closest competing card Radeon RX 6800 XT, which we test both with and without Smart Access Memory activated. A total of nine games are tested at three different resolutions, all of which are on Nvidia’s compatibility list of titles supported with Resizable BAR.

Game tests in 1,920 × 1,080 pixels

We start with the 1080p resolution and quickly see that there are definitely nice performance gains to be made with the help of Resizable BAR. Geforce RTX 3080 wins the most in Battlefield V, where the frame rate increases by 10 percent. Assassin’s Creed and Borderlands 3 can also enjoy an upswing of 9 and 8 percent, respectively. However, there are also examples where zero and nothing happens, which in this case is about Gears 5 and Metro Exodus.

For the Radeon RX 6800 XT, additional impressive performance results are seen with Smart Access Memory enabled. In Red Dead Redemption 2, we see an upswing of as much as 17 percent, while Assassin’s Creed can enjoy a profit of 16 percent. Borderlands 3 and Cyberpunk 2077 also impress with upswings of 15 and 13 percent respectively. Like the Nvidia card, however, there are cases where SAM does not make a profit at all, including in Battlefield V, Metro Exodus and Watch Dogs Legion.

The average performance boost for Geforce RTX 3080 with Resizable BAR enabled at this resolution is 5 percent. The corresponding figure for the Radeon RX 6800 XT with Smart Access Memory lands at 8 percent.

Game tests in 2,560 × 1,440 pixels

With the step over to the resolution 1440p, it is interesting to see how the performance gains are shuffled significantly between the different game titles. The Geforce RTX 3080 gets the biggest performance boost with Resizable BAR in Forza Horizon 4 with 10 percent higher numbers. At the same time, there are great wins to be made in both Watch Dogs Legion and Assassin’s Creed with 9 and 8 percent performance increases, respectively. At this resolution, only Metro Exodus does not gain anything from the technology being activated.

For AMD’s Radeon RX 6800 XT, an extremely impressive performance boost can be seen in Forza Horizon 4, where the frame rate rises by as much as 23 percent when SAM is activated. Assassin’s Creed and Red Dead Redemption 2 also show nice gains of 13 percent, closely followed by Cyberpunk 2077 and Gears 5 of 11 percent performance gain. Once again, however, performance stands still in Metro Exodus and Watch Dogs Legion.

The average performance boost for Geforce RTX 3080 with Resizable BAR enabled at this resolution is 6 percent. The corresponding figure for the Radeon RX 6800 XT with Smart Access Memory lands at 9 percent.

Game tests in 3,840 × 2,160 pixels

Over to the last and heaviest resolution, where the percentage performance gains decrease slightly for the Geforce RTX 3080 when Resizable BAR is activated. The best results can be seen in Assassin’s Creed, which fluctuates by 8 percent. Then Forza Horizon 4 and Watch Dogs Legion appear with wins of 7 percent. Metro Exodus is once again completely stationary on the performance front.

The gains are also reduced for the Radeon RX 6800 XT, although it can still boast quite impressive figures from Forza Horizon 4 which wins a full 18 percent performance with SAM enabled. In addition, it is mainly Assassin’s Creed that is notable with its nice performance boost of 9 percent. Among the games that stand still in terms of performance are Metro Exodus and Watch Dogs Legion.

The average performance boost for Geforce RTX 3080 with Resizable BAR enabled at this resolution is 4 percent. The corresponding figure for the Radeon RX 6800 XT with Smart Access Memory lands at 5 percent.

Summary thoughts on Resizable BAR together with Geforce RTX 3080

With the numbers in front of us, we can state that it is definitely worth activating Resizable BAR on Geforce RTX 3080. In practice, this is a free performance waiting to be extracted, where in some titles you can enjoy a boost in frame rate of as much as 10 percent. The average result on more games is lower, but still at a modest 5 percent if we beat it over the tested resolutions.

In comparison with the competitor AMD’s Radeon RX 6800 XT, however, it must be said that the gains are not quite as impressive from Nvidia’s point of view. Whether Resizable BAR works better on RDNA 2 or if AMD has a secret sauce in its drivers for Smart Access Memory is unclear, but it is clear that the company can in some cases excel with performance upswings that land north of the 20 percent mark.

Have you tested Resizable BAR with the Geforce RTX 3000 series? Share your experiences in the comment thread!