Resizable BAR (SAM) causes performance degradation

What is RESIZABLE-BAR-ERROR?

This low-severity issue affects the graphics card (GPU). FPS drops in some games after enabling Resizable BAR (AMD Smart Access Memory) or nVidia NVLink. This usually traces back to an outdated VBIOS of the video card does not fully support ReBAR and incorrect configuration of Above 4G Decoding in BIOS. See the troubleshooting steps below for the fix.

Common Causes

• An outdated VBIOS of the video card does not fully support ReBAR
• The game does not have a profile for Resizable BAR (blacklist)
• Incorrect configuration of Above 4G Decoding in BIOS

Step-by-Step Fix Guide

• 1
  Update both board BIOS and graphics card VBIOS

  Update both board BIOS and graphics card VBIOS tends to be the quickest win here, addressing the most typical cause of RESIZABLE-BAR-ERROR.

• 2
  Make sure Above 4G Decoding is turned on BEFORE enabling ReBAR

  If the fault persists, continue with the next steps, which account for less common gpu instability causes.

• 3
  Test performance with ReBAR on and off

  "Test performance with ReBAR on and off" is worth trying when an outdated VBIOS of the video card does not fully support ReBAR turns out to be the culprit.

Commands & Diagnostics

Frequently Asked Questions