How to Enable AMD Smart Access Memory

What AMD Smart Access Memory Does

AMD Smart Access Memory is the AMD name for Resizable BAR, a feature of the PCI Express standard. With the setting off, the processor in a desktop can only reach a limited portion of the memory on the graphics card. With it on, the CPU can address the full graphics memory, so data the GPU has placed in its own memory can be read directly by the processor instead of moving through a small fixed window.

The feature appears under two names. Motherboard firmware often lists it as Re-Size BAR Support or Resizable BAR, while the AMD Radeon software calls it Smart Access Memory. Both names point to the same mechanism, so the toggle in the BIOS and the status readout in the driver software refer to the same setting. For the generic name used across other hardware, see the article on enabling Resizable BAR.

Which Parts Support It

Smart Access Memory needs three parts on one desktop: a compatible AMD Ryzen processor, a Radeon graphics card, and a motherboard built around an AMD chipset. The motherboard's BIOS version must already contain the toggle. A board that shipped before the feature existed may need a newer BIOS before the option appears, and updating the firmware is a separate task from the steps in this guide.

The feature travels over the PCI Express link between the CPU and the GPU, so the card should sit in the primary PCIe x16 slot. Vendor comparison pages for the latest desktop graphics families list PCI Express Gen 4 and Gen 5 support, which means the link itself is not the limiting factor on a recent board. Motherboards built for current Ryzen CPUs are covered in the AM5 motherboard guide.

What to Check Before You Start

Update the Radeon driver before changing the setting. A current driver gives the clearest readout of the Smart Access Memory status in the AMD Radeon software, which is how you confirm the change after the BIOS saves and reboots. The steps for a clean driver update are in the graphics driver guide.

The setting lives in the motherboard's UEFI firmware, not in Windows. Microsoft's Windows 11 system requirements list UEFI with Secure Boot capability as a firmware requirement, so a recent desktop running Windows 11 is already using the kind of firmware that holds this option.

How to Enable It in the BIOS

The exact menu names differ slightly between motherboard makers, but the order is the same. Look for the setting in the advanced PCI or chipset section of the UEFI, not in the driver software; no Windows tool turns this feature on.

• Restart the desktop. As it starts, press the key the motherboard displays on screen, often Delete or F2, to open the UEFI setup screen.
• Open the Advanced menu, then a PCI Subsystem or similar section. The exact names vary by motherboard maker.
• Find the Above 4G Decoding toggle and set it to Enabled.
• Find the Resizable BAR toggle, which may be labeled Re-Size BAR Support or Smart Access Memory, and set it to Enabled.
• Press the save-and-exit key, commonly F10, and let Windows boot normally.
• Open the AMD Radeon software and check the performance page for the Smart Access Memory status. An active reading means the feature is on.

Related Firmware Settings on the Same Screen

Above 4G Decoding and Resizable BAR usually sit on the same firmware screen and work together. The first toggle widens the address space the firmware maps for the card, and the second lets the CPU reach the full graphics memory. Enable both at the same time; turning on only one leaves the feature incomplete.

Other firmware screens on a gaming desktop hold unrelated but useful settings, such as the memory profile toggle for the RAM kit and the boot-order list. The memory profile guide covers the RAM setting, and the BIOS settings guide reviews the firmware options that matter most for games.

What It Changes in Play

The benefit appears in scenes where the CPU has to fetch data the GPU has stored in its own memory, which is common in large open-world single-player games where the processor tracks a great deal of world state. Full access to the graphics memory lets the CPU read what it needs without the older limited-window method.

Smart Access Memory does not add graphics memory. It changes how the CPU reaches the memory already on the card, so it does not replace the need for a card with enough VRAM for the resolution you play at. The guide to graphics memory for a gaming PC covers the memory tiers for each resolution.

For a competitive shooter played at a high refresh rate, the setting plays a smaller part, because those scenes lean more on the GPU and on the monitor's refresh rate. See the guide to good refresh rates for gaming for that side of play.

If the Option Is Missing or the System Will Not Boot

If the Resizable BAR toggle does not appear in the UEFI, the BIOS on the board does not offer the feature for the installed CPU and GPU. The option is tied to the specific pairing, so a combination that was not listed as compatible may simply lack the setting. A prebuilt gaming PC that lists a Ryzen processor and a Radeon card is more likely to include the option in its firmware.

If the desktop does not boot after you enable the setting, enter the UEFI again and set both toggles back to Disabled. The machine then starts with the previous firmware configuration. Reverting a BIOS option is a normal step for this kind of change, not a repair.

What to pick for your play

Questions

Is Smart Access Memory the same thing as Resizable BAR?

Yes. Smart Access Memory is AMD's name for Resizable BAR. The motherboard firmware often labels the setting Re-Size BAR Support or Resizable BAR, and the AMD Radeon software calls it Smart Access Memory. Both refer to the same mechanism.

Which parts do I need to enable it?

A compatible AMD Ryzen processor, a Radeon graphics card, and an AMD chipset motherboard whose BIOS includes the toggle. The motherboard's compatibility listing is the best place to confirm the exact CPU and GPU models.

Can I enable it on a prebuilt gaming desktop?

Yes, if the prebuilt uses a compatible Ryzen CPU, a Radeon GPU, and an AMD chipset board. Enter the UEFI setup the same way and look for the toggle. If the option is missing, the board does not offer it for that combination.

Does the setting replace the need for more graphics memory?

No. Smart Access Memory changes how the CPU reaches the memory already on the card. It does not add memory, so the amount of VRAM on the card still decides what resolution and texture detail the card can hold.

Why does the option not appear on my machine?

The BIOS version may predate the feature, or the installed CPU and GPU may not be a compatible pairing. Confirm the model names and check the motherboard's BIOS information for Resizable BAR support.