So for the past few months I've been trying to get SAM working on my Radeon RX 5600 XT video card with mixed results: the driver says it's enabled, but when looking at the "resources" tab (via the device manager), it only shows 1GB memory range when I would expect it to show the full card's 6GB (as can be seen when using a 5700XT card, which shows 8GB). The performance with SAM enabled is heavy impacted, especially in games (the frame time increases almost 3x!).
Is this the normal behavior for this card? can something be done to improve the situation?
System specs: Ryzen 5 3600, Sapphire Pulse RX 5600 XT, Gigabyte B450M DS3H, Corsair 2x8GB 3000C16 ram
Drivers: Graphics - 22.2.3, Chipset - 3.10.08.506 (also tried with Gigabyte latest - 18.104.22.1686)
Bios: Currently using F63a (AGESA V2 22.214.171.124 B), in the past I've seen the same results with older versions : F62 (AGESA ComboV2 126.96.36.199 A), F61 (GESA ComboV2 188.8.131.52 B), and F60 (AGESA ComboV2 184.108.40.206).
According to SAM Requirements you needs a 500 series motherboard. 400 series Motherboards doesn't support SAM. Also need a 6000 series GPU card. The 5000 series GPU cards doesn't support SAM.
Here is AMD SAM Requirements from AMD: https://www.amd.com/en/technologies/smart-access-memory
This other tech website also mentions the same requirements for SAM: https://www.windowscentral.com/how-smart-access-memory
AMD's Smart Access Memory is essentially "resizable Base Address Register (BAR) support" with a fancy name. The technology actually came along with PCIe 3.0, and AMD isn't alone in offering this feature. In early 2021, NVIDIA added resizable BAR support to its RTX 30-series GPUs through a driver update.
In order for SAM to work on your PC, you must have certain hardware components.
Our guide on where to buy AMD Radeon RX 6000 GPUs might be able to help, as can our collections of best motherboards. As long as you have this hardware in your PC, and as long as your GPU driver and BIOS are up to date, you should be able to jump in and enable SAM with the steps below.
First AMD Drivers doesn't know if your Motherboard is a 500 series motherboard that you have it installed in.
Second, most likely the same AMD driver for 5000 series GPU Cards is the same for the 6000 Series GPU cards that does support SAM.
I don't know if with a Driver you can make the 5000 series GPU Cards compatible or not but it does definitely mention you need a 500 Series Motherboard. Seems like the 400 series or older Motherboards doesn't have the electronic circuitry to support SAM.
Check in GPU-Z Advanced section (rbar disabled in my pic), all requirements should state yes if supported.
I just got a 5600XT, found this topic, and was little bit sad.
But lo and behold, AMD FineWine™ in action.
I'm using B350M MSI Mortar motherboard, Ryzen 5500 and XFX 5600XT.
Found the resizable bar BIOS toggle in BIOS (you have to have the latest available BIOS), enabled it, and from that moment I could enable AMD SAM in Radeon settings (under Performance -> Tuning -> AMD SmartAccess Memory
Just wanted to chime in, in came anyone else is looking for this in future.
Did it improve the performance?
I'm playing with a Ryzen 3 3100, B550 motherboard and the Gaming X model of the 5600xt, and enabling SAM makes my gaming performance actually worse than having it disabled in games like Watch Dogs Legion or Cyberpunk 2077.
Maybe because you have that weak CPU. If it needs to allocate bigger buffers on PCI-E it will have more overhead if you are CPU bound.
It works fine for me on that GPU and Ryzen 3600 on a B450, but on Nimez drivers.
This is just a quick update to lat anyone interested that I have figured out the problem (spoiler: "VBIOS" :(), as you can see from the attached image, the GPU does not report the correct bar size (1GB only). Everything is enabled (or auto) in the BIOS, drivers are up to date and SAM is on, performance is still bad even when compared to the same settings with SAM off!
A fix would have to come from AMD (or probably from the card's vendor) in the form of a modified VBIOS.