Changing This One Setting Can Grab You Some Extra Gaming Performance (2024)

Did you know that with the right BIOS setting, you can squeeze out additional performance from your existing hardware? If you aren’t aware of Resizable BAR and how it boosts performance, there is a good chance you may have it disabled. Here’s how you can enable a Resizable Bar and what to expect from it.

What Is Resizable BAR?

Resizable BAR (Base Address Register) is a feature that allows the CPU to access the entire graphics card memory, or VRAM, at once instead of in small, fixed-size chunks of 256MB. This feature is part of the PCI Express standard and aims to improve the efficiency of data transfers between the CPU and GPU, enhancing overall system performance for GPU-intensive games and applications.

How Does Resizable BAR Work?

Under normal circ*mstances, the CPU can only access a portion of the GPU's memory at a time due to the limitations of the traditional PCIe standard. With Resizable Bar disabled, the default bandwidth is limited to only 256MB at a time. This limited bandwidth can create bottlenecks, especially in data-intensive tasks like gaming, video editing, and simulations.

Resizable BAR removes these limitations by allowing the CPU to access the entire VRAM in a single operation. This increases the speed at which data is transferred between the CPU and GPU, leading to improved performance in supported games and applications.

AMD Smart Access Memory

AMD's implementation of Resizable BAR is known as Smart Access Memory (SAM). Introduced with the Ryzen 5000 series CPUs and Radeon RX 6000 series GPUs, SAM allows these components to communicate more efficiently, leveraging the full potential of the hardware. AMD claims up to a 16% improvement in gaming performance with SAM enabled, though actual gains may vary depending on the game and specific hardware configuration.

Hardware Requirements for Resizable BAR

To utilize Resizable BAR, your system must meet certain hardware requirements:

1. CPU: AMD Ryzen 5000 series or newer, Intel 10th Gen or newer.
2. GPU: NVIDIA RTX 30 series or AMD Radeon RX 6000 series or newer.
3. Motherboard: Must support Resizable BAR, which typically requires a BIOS update. AMD motherboards supporting SAM would start with their 400 and 500 series of motherboards (e.g. X570, B550, A520, X470, B450). While Intel would also start with their 400 and 500 series of motherboards (Z590, B560,Z490, H470, B460, H410). Newer generation motherboards will likely support Resizable BAR, especially gaming and higher end motherboards.

Make sure to check your motherboard manufacturer's website for BIOS updates that enable Resizable BAR support.

Use GPU-Z for a Quick Way to Check Resizable BAR Status

Before enabling Resizable BAR, you can check its status using GPU-Z. GPU-Z is a popular utility for monitoring graphics card information. To check if Resizable Bar is enabled, download GPU-Z and install it. Once installed, open GPU-Z and look for the "Resizable BAR" entry to see if it's enabled or disabled. This can save you time by confirming whether your system already supports the feature. If Resizable BAR is disabled, you can enable it through the BIOS, which we will discuss shortly.

What Performance Benefits Can You See?

Enabling Resizable BAR can lead to performance improvements in a variety of games by reducing latency and accessing GPU memory over the 256MB limit per instant. AMD claims up to 16% performance boost on some games, for example, though real-world benefits can vary. Many users report performance gains in the range of 6-10%, with some games showing even higher improvements. It is important to note that games will not benefit equally, and a few might even experience slight performance drops. That is why it’s important to test your games first to understand the true impact of Resizable BAR in terms of performance.

How to Enable Resizable BAR

If your system has a CPU, GPU, and a motherboard that supports Resizable BAR, you can easily enable this setting using your BIOS. Enabling Resizable BAR only takes a few steps. Here’s how:

Step 1:Enter BIOS

Restart your computer and enter its BIOS by pressing DEL or F12 key during boot. Some motherboards may use different keys to enter BIOS. A quick search online should tell you which key you need to press for your specific motherboard.

Step 2: Enable Above 4G Decoding

In your computer’s BIOS, navigate to the PCIe settings menu and enable Above 4G Decoding. This setting enables 64-bit address space for your PCIe devices, allowing access to over 4GB of memory space per PCI Express device such as your GPU.

Step 3: Enable Resizable BAR Support

Now that you have enabled 64-bit addressing, navigate to Re-Size BAR and switch to enable. This option may be listed under different names depending on your motherboard manufacturer. AMD may call it Smart Access Memory (SAM), while Nvidia uses Re-Size BAR or Resizable BAR.

Some motherboards may have Above 4G Decoding and Resize BAR settings coupled into one. If so, switching Re-Size BAR to enable should also enable Above 4G Decoding.

Step 4: Save and Exit

Make sure that all the changes are made to the current XMP/EXPO profile you’re using before hitting save and exit. After rebooting, check GPU-Z to confirm that Resizable BAR is enabled.

If your system fails to boot or you encounter issues, you may need to disable CSM (Compatibility Support Module) and ensure your system drive uses the GUID Partition Table (GPT) rather than the older MBR format.

While Resizable BAR can provide a free and relatively easy performance boost, it’s not without potential drawbacks. Some games might not see any benefit, and a few might even perform worse. Additionally, the process of enabling this feature involves BIOS changes, which carry a small risk of causing system instability if not done correctly. Always ensure you have the latest BIOS and drivers, and proceed with caution.

Overall, if you're looking to get the most out of your gaming rig, enabling Resizable BAR is a worthwhile tweak to explore. It offers the promise of better performance at zero cost, making it an attractive option for gamers and PC enthusiasts alike.