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Resizable BAR (Base Address Register) is a feature that allows the CPU to access the entire GPU memory buffer at once, improving gaming and application performance. Enabling this feature requires changes in the BIOS settings, which can vary across different motherboard brands. Understanding these differences can help users optimize their systems effectively.
Understanding Resizable BAR
Resizable BAR is part of the PCI Express (PCIe) specification and is supported by many modern CPUs and GPUs. When enabled, it allows the system to access the full GPU memory, reducing bottlenecks and enhancing performance in many applications, especially gaming.
BIOS Settings for Resizable BAR Activation
Activating Resizable BAR involves enabling specific BIOS settings. However, the terminology and location of these settings differ among motherboard manufacturers. Below is a comparison across popular brands.
ASUS
In ASUS BIOS, look for the “Resizable BAR Support” option, usually found under the Advanced > PCIe settings. It must be set to Enabled. Additionally, ensure that “Above 4G Decoding” is enabled, which is often a prerequisite.
MSI
MSI motherboards typically list “Resizable BAR” under the Settings > Advanced > PCIe Configuration menu. Toggle the option to Enabled. Like ASUS, enabling “Above 4G Decoding” is recommended for stability and compatibility.
Gigabyte
Gigabyte BIOS includes a “Resizable BAR” option within the Settings > PCIe Configuration menu. Set it to Enabled. Also, verify that “Above 4G Decoding” is activated to support Resizable BAR functionality.
Common BIOS Settings and Tips
- Above 4G Decoding: Enable this setting on all brands to support Resizable BAR.
- PCIe Slot Configuration: Ensure the primary GPU is installed in the correct PCIe slot that supports Resizable BAR.
- Firmware Updates: Keep BIOS firmware updated to the latest version, as support for Resizable BAR is often added through updates.
- Compatibility: Check your CPU and GPU compatibility with Resizable BAR before enabling.
Enabling Resizable BAR: Step-by-Step
Follow these general steps to enable Resizable BAR across different brands:
- Enter BIOS during system startup (usually by pressing Del or F2).
- Navigate to the PCIe or Advanced settings menu.
- Locate the “Resizable BAR” or “Resizable BAR Support” option.
- Set the option to Enabled.
- Ensure “Above 4G Decoding” is also enabled.
- Save changes and exit BIOS.
- Boot into Windows and verify the feature is active using system information tools or GPU utilities.
Verifying Resizable BAR Activation
After enabling Resizable BAR, confirm its activation through tools like GPU-Z, HWInfo, or the system BIOS itself. You should see an indication that the feature is active, which can lead to improved performance in supported applications.
Conclusion
While the process of enabling Resizable BAR varies slightly across motherboard brands, the core requirements remain consistent: enable the feature in BIOS and activate “Above 4G Decoding.” Keeping BIOS firmware updated and verifying compatibility ensures optimal performance gains from this technology.