Smart Access Memory on Zen 2 CPUs – The Power of Resizable Bar!

AMD’s Smart Access Memory technology is groundbreaking. While the same technology can be implemented on Intel processors and Nvidia graphics cards, it cannot be denied that AMD broke this ground first. 

With or testing today, we can confirm that the benefits of AMD’s Smart Access Memory/Resizable BAR support is not limited to Ryzen 5000/Zen 3 processors and that Zen 2 users can see significant performance increases if their motherboard and graphics card both support the feature. 

Smart Access Memory is pure magic, allowing some games to smash through previously hidden performance limitations. Assassin’s Creed Valhalla and Forza Horizon 4 are both great examples of this, though it is worth noting that some games will see no performance benefits from Smart Access Memory. Giving CPUs access to more GPU resources won’t benefit performance if games cannot utilise those extra resources. 

Most performance data related to Smart Access Memory focuses on Average framerates, but out testing shows that many games see larger gains in minimum framerates, cutting down the severity of some performance dips while granting gamers more stable performance. In Assassin’s Creed Valhalla, our Radeon RX 6800 delivered 1st percentile framerate results that were almost 30% higher at 4K, and if this is not an impressive result, I don’t know what is. 

You can be sure that Nvidia will implement a similar feature within its Geforce drivers in the future. The performance benefits of Smart Access Memory/ Resizable BAR support on AMD hardware is too much for Geforce to ignore. Future games may also be developed with this technology in mind, making this a critical feature for future game releases. With all next-generation consoles offering combined CPU/GPU memory, it makes sense for GPUs to start giving CPUs more access to their memory pools. 

While some fanboys will call Resizable BAR support a PCIe feature to discredit AMD’s innovation, it is worth noting that this feature requires CPU support, motherboard support, GPU support, and driver support to function correctly. Only AMD had the ability to put everything in place to lay the groundwork for everyone else. Intel doesn’t make high-end gaming graphics cards, and Nvidia doesn’t make x86 processors for gaming PCs. AMD needed to implement this feature across their motherboards and GPU drivers to make things work.

Today’s games are not designed with Smart Access Memory in mind, so it is also worth noting that we experienced no notable stability issues when using Smart Access Memory on AMD’s Radeon RX 6800. Credit where credit is due, that feat must have requires a lot of effort on the part of Radeon’s driver team, and that QA is likely the reason why Nvidia has been unable to implement a similar feature within their GPU drivers quickly.

With the right BIOS and a supported graphics card, Smart Access Memory/Resizable BAR support is possible on Ryzen 3000 series/Zen 2 CPUs. If your motherboard, CPU and graphics card supports it, it is a feature that is definitely worth enabling, especially if you play games like Forza Horizon 4 and Assassin’s Creed Valhalla. Only time will tell how this feature will change how PC games utilise hardware, though you can bet that it will become an almost mandatory feature in some future games. 

You can join the discussion on using Smart Access Memory/Resizable Bar on Zen 2 processors on the OC3D Forums.