Resizable BAR (Base Address Register) is a PCI Express interface technology that enables the CPU to access the entire GPU video memory (VRAM) pool simultaneously, rather than being restricted to sequential 256MB chunks. While modern NVIDIA RTX 30, 40, and 50-series cards support Resizable BAR, the official NVIDIA display driver only enables it out-of-the-box for a small, pre-approved whitelist of games.
By utilizing NVIDIA Profile Inspector, you can manually force Resizable BAR on unsupported games or tweak the BAR size limit to eliminate micro-stutters and improve 1% low frame rates in memory-heavy titles.
Hardware & BIOS Prerequisites
Before modifying driver profiles, Resizable BAR must be enabled at the motherboard and hardware level:
- Motherboard BIOS: Above 4G Decoding must be Enabled and Resizable BAR Support set to Enabled / Auto.
- Partition Style: Windows must be installed in UEFI mode (GPT partition style). Legacy CSM (Compatibility Support Module) must be disabled.
- GPU Hardware: NVIDIA GeForce RTX 30-series (with updated VBIOS), RTX 40-series, or newer desktop/laptop GPUs.
- Driver Version: GeForce Game Ready Driver 465.89 or higher.
Quick Verification: Open the standard NVIDIA Control Panel, click Help > System Information, and confirm that Resizable BAR: Yes is listed.
The 4 Key Resizable BAR Profile Flags
In NVIDIA Profile Inspector, navigate to the target game profile (or create a custom profile) and scroll to Section 07 – System, Memory and Compute. You will configure four distinct driver parameters:
| Parameter Name | Setting Hex ID | Recommended Value | Technical Function |
|---|---|---|---|
| rBAR – Enable | 0x000F00BA | 0x00000001 (Enabled) | Toggles the profile-level Resizable BAR state. |
| rBAR – Options | 0x000F00BB | 0x00000001 | Specifies the primary driver option bitmask for BAR mapping. |
| rBAR – Size Limit | 0x000F00FF | 0x0000000040000000 (1GB) | Defines the allocated memory bar limit (Default: 1GB; 4GB optional for high-VRAM mods). |
| rBAR – Intel CPU Exclusion | 0x00E942FC | 0x00000000 | Clears the CPU exclusion mask (ensures Intel 10th-14th Gen processors utilize BAR). |
Step-by-Step Setup Guide in NVIDIA Profile Inspector
- Launch Elevated: Right-click
nvidiaProfileInspector.exeand select Run as administrator. - Locate Game Profile: In the top Profiles search bar, type the name of your game (e.g., Starfield, The Witcher 3, or a customized Unreal Engine title) and select it.
- Configure Section 07:
- Locate rBAR – Enable and switch the value from 0x00000000 to 0x00000001 (Enabled).
- Locate rBAR – Options and select 0x00000001.
- Locate rBAR – Size Limit and select 0x0000000040000000 (1GB).
- Apply Modifications: Click Apply changes in the top-right corner. The changes are immediately committed to the NVIDIA DRS database without requiring a reboot.
When to Avoid Forcing Resizable BAR
While Resizable BAR generally improves 1% low frame rates and smooths asset streaming in modern titles (DirectX 12 and Vulkan), certain older DirectX 11 titles or unoptimized game ports may experience slight frame rate regressions (1–3% drop). If you encounter micro-stuttering after forcing ReBAR in a specific game, revert the profile setting back to Disabled (0x00000000) or click the green restore button in Profile Inspector.
Download Required Utility
To configure these driver flags, make sure you are running the verified release of NVIDIA Profile Inspector:
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