If you’ve been exploring BIOS settings or GPU features on your gaming PC, you’ve likely come across Resizable BAR. This feature can help improve performance, reduce bottlenecks, and better utilize modern hardware.
But you might be wondering, “What is Resizable Bar?” “How much does it actually help?” And (most importantly), “Is it worth enabling?”
What Is Resizable BAR?
Short for Resizable Base Address Register, Resizable BAR is a PCIe feature that allows the CPU to access the full memory capacity of your graphics card (VRAM) at once, rather than in small, fixed segments.
Under normal circumstances, a CPU can only access a small portion of the GPU’s VRAM at a time. This limitation comes from older PCIe standards and was rarely a problem when GPUs had far less memory.
However, modern graphics cards now often feature 8GB, 12GB, 16GB, or more of VRAM. With large, high-resolution textures and expansive game worlds, constantly swapping small memory segments can become a pain.
Resizable BAR removes this restriction, allowing the CPU to access the entire GPU framebuffer directly. When it’s enabled, you get more efficient data transfers between the processor and the graphics card, potentially improving gaming performance.
How Resizable BAR Works
To understand how Resizable BAR works overall, it also helps to know the basics of how the CPU and GPU communicate.
Communication between the CPU and GPU looks like:
The CPU sends rendering instructions to the GPU.
GPU stores textures, geometry, and frame data in VRAM.
CPU accesses portions of that VRAM via PCIe to manage workloads.
Traditionally, the CPU “sees” the GPU’s memory through a limited window. With the Resizable BAR enabled, the window expands, giving the CPU full visibility into VRAM.
Performance Impact: Does Resizable BAR Improve FPS?
With FPS, the potential performance gains will vary by game, GPU, and the system’s configuration. Some games may show minimal differences, and in rare cases, performance may remain unchanged.
The games that benefit most from Resizable BAR tend to:
Use large texture files
Stream assets dynamically
Rely heavily on CPU-to-GPU communication
It’s important to understand that Resizable BAR is not a magic performance switch. It really only optimizes memory access efficiency, not increases raw GPU horsepower.
Requirements for Resizable BAR
To use the Resizable BAR feature, your system must support it at multiple levels:
Compatible CPU: Most 10th Gen Intel Core (and newer) and AMD Ryzen 3000-series (and newer) processors support it, depending on chipset and BIOS updates.
Compatible GPU: GPU support varies by manufacturer. So, the NVIDIA RTX 30 series and newer, AMD RX 6000 series and newer, or Intel Arc GPUs are all good. Anything else, you should verify before trying to enable Resizable BAR.
Updated Drivers: Make sure your GPU drivers also support Resizable BAR functionality.
Motherboard Support: Not only does your motherboard need to support UEFI BIOS, but it also needs a BIOS update that enables Resizable BAR and is above 4G Decoding.
If any one of these components lacks support, the Resizable BAR feature will not activate.
How to Enable Resizable BAR
Update your motherboard BIOS to the latest version
Update your GPU drivers
Enter BIOS/UEFI settings
Enable “Above 4G Decoding” and “Resizable BAR Support” (the wording might differ slightly)
After saving and rebooting, confirm the activation using your GPU control panel or system information tools. Before making any BIOS changes, double-check that your system is stable and that you can revert settings if necessary.
Is Resizable BAR Worth Turning On?
For the most part, Resizable Bar is worth turning on for any modern system. As long as you have a compatible CPU, a supportive GPU, and a motherboard with BIOS support, you’re good to go.
If your system supports it, it’s a smart optimization to enable for texture-heavy and next-gen games. That said, if you’re using older hardware or unsupported components, enabling it may not be beneficial, or even possible.
Have more questions about gaming PCs?
Check out our support blog to learn more about how to build the best gaming PC for those long gaming sessions.
FAQs about Resizable Bar
Does Resizable BAR work on all GPUs?
Resizable BAR doesn’t work for all GPUs, especially older ones. For Resizable BAR to work, the GPU needs hardware support, a BIOS that enables it, and driver support.
Is Resizable BAR the same as Smart Access Memory?
Resizable BAR is the same as Smart Access Memory. There are slight differences since Smart Access Memory is AMD’s version of Resizable BAR, but the basics are similar.
Does Resizable BAR work in all games?
Resizable BAR doesn’t work for all games. Any performance gains depend on how the game engine handles CPU-to-GPU memory communication.
