How to Check If Resizable BAR Is Enabled on AMD Radeon (Windows 10/11)

Resizable BAR lets your CPU access more of your GPU’s memory at once (instead of a small window), which can help performance in some games. On AMD, it’s usually labeled SmartAccess Memory (SAM) inside Adrenalin. Just don’t expect miracles: some games benefit, some don’t, and sometimes the gain is small.

Below are the fastest ways to confirm whether it’s actually enabled—and what to fix if it isn’t.

What Resizable BAR Means on Radeon

Resizable BAR is a PCIe feature that increases how much GPU memory the CPU can address in one go. AMD markets it as SmartAccess Memory on Radeon. If you’re tweaking settings for extra FPS, this is one of the “check first” items—because it’s easy to think it’s enabled when it’s not.

Fastest Method: Check in AMD Software

1) Open Adrenalin

• Right-click your desktop → AMD Software: Adrenalin Edition.

2) Check the main dashboard first (fastest)

On many versions, SmartAccess Memory shows on the Home/Dashboard page in a small status panel (often near the lower-left area).

• If it says Enabled, you’re done.

3) If you don’t see it, use Settings

• Click the gear icon (Settings).
• Go to System (common spot), and look for SmartAccess Memory.

• If your layout looks different, use the search bar (if available) and type:

  • SmartAccess Memory
  • SAM

4) What the status means

• Enabled → Resizable BAR is on.
• Disabled → Your hardware supports it, but it isn’t switched on (usually BIOS).
• Not Available → Something is blocking it (commonly CSM/UEFI mode, missing BIOS options, or outdated BIOS firmware).

Confirm in Windows: Use GPU-Z

Adrenalin is the convenient check. GPU-Z is the “trust but verify” check.

1) Run GPU-Z

Download GPU-Z, launch it (portable is fine).

2) Find the Resizable BAR readout

• Go to the Advanced tab
• Use the drop-down and select PCIe / Resizable BAR (wording varies)

You’ll typically see one of these:

• Resizable BAR: Enabled
• Supported, Disabled
• Not Supported

If Adrenalin and GPU-Z disagree, treat GPU-Z as the more direct “is it active” readout—then use the BIOS section below to fix what’s blocking it.

Confirm at the Source: BIOS/UEFI Settings That Must Be Right

If you see Disabled or Not Available, BIOS is where this gets resolved.

1) Enter BIOS/UEFI

Restart and tap Delete or F2 (most motherboards).

2) Enable these two settings

• Above 4G Decoding → Enabled
• Resizable BAR Support / Re-Size BAR → Enabled

3) Disable this one

• CSM (Compatibility Support Module) → Disabled

4) Save and reboot

Boot back into Windows, then re-check:

• Adrenalin: SmartAccess Memory
• GPU-Z: Resizable BAR

Where these settings live depends on your motherboard brand, but they’re usually under Advanced, PCIe settings, or Boot.

If It Still Says “Not Available” or “Disabled”

1) Windows boot/install mode mismatch (UEFI + GPT matters)

Even if you flipped the BIOS toggles, a legacy-style Windows setup can stop Resizable BAR from activating.

Check your OS drive:

• Open Disk Management
• Right-click your Windows drive → Properties → Volumes

• Look for Partition style:

  • GPT = good
  • MBR = often a problem for UEFI-only features

Don’t change anything blindly—verify first, then decide your path.

2) Your motherboard BIOS is outdated

A lot of boards gained proper Resizable BAR support (or stability) through BIOS updates.

• Update to the latest stable BIOS from your motherboard vendor

• After updating, go back in and re-check:

  • Above 4G Decoding
  • Resizable BAR
  • CSM (updates often reset BIOS settings)

3) Driver is too old (or the install is messy)

• Install the latest AMD Adrenalin driver package
• If you’ve swapped GPUs or installed drivers repeatedly over time, consider a clean reinstall so old bits aren’t lingering

4) GPU in the wrong slot

On many boards, only the primary slot is wired ideally for full features/performance.

• Put the GPU in the top/main PCIe x16 slot (usually closest to the CPU)

5) Platform limitation

If GPU-Z reports Not Supported, your current CPU/motherboard combo likely can’t do Resizable BAR—even if the GPU itself can.

Quick Checklist

• BIOS

  • Above 4G Decoding: ON
  • Resizable BAR: ON
  • CSM: OFF

• Windows

  • Boot mode: UEFI
  • OS drive: GPT

• Drivers

  • Recent AMD Adrenalin

• Verify

  • Adrenalin: SmartAccess Memory = Enabled
  • GPU-Z: Resizable BAR = Enabled

• Expectations

  • Don’t panic if a specific game shows little to no gain—results vary.

FAQ

Resizable BAR vs Smart Access Memory—are they the same on Radeon?

On AMD, SmartAccess Memory (SAM) is the Radeon-facing name for Resizable BAR. If SAM is enabled, you’re effectively running Resizable BAR.

Can I enable Resizable BAR without updating BIOS?

Sometimes, yes. But if your system reports Not Available, a BIOS update is one of the most common fixes—especially on older firmware.

Will it cause instability?

Most systems are fine with it on. If you run into crashes, double-check BIOS stability, remove aggressive overclocks/undervolts, and make sure your driver install is clean.

GPU-Z says “Supported, Disabled”—what does that mean?

Your hardware can do it, but it’s not enabled. Go back to BIOS and confirm:

• Above 4G Decoding = Enabled
• Resizable BAR = Enabled
• CSM = Disabled

Why does my PC boot into BIOS after enabling Resizable BAR?

This usually happens because enabling Resizable BAR (and Above 4G Decoding) pushes your system into a UEFI-only boot setup, but your Windows installation is still configured for Legacy/MBR. When the motherboard can’t find a valid UEFI boot target, it drops you back into BIOS instead of loading Windows.