How to Enable Resizable BAR on a Gaming PC

What Resizable BAR does and why it matters for PC gaming

A graphics card holds its own video memory (VRAM), where textures and geometry are stored for quick access. Without Resizable BAR, the CPU can only read and write to a small window of that memory at a time, typically 256 MB. This forces the system to shuffle data through the PCIe bus in small chunks, which can create a bottleneck in games that load large assets.

Resizable BAR changes this by allowing the CPU to address the full VRAM capacity at once. It is a feature of the PCI Express specification, and it is available on many modern motherboards, processors, and graphics cards. When enabled, the CPU can send requests to the entire graphics memory, which can reduce latency and improve performance in scenes that depend on frequent asset streaming

The exact gains depend on the game and the rest of the system. Some titles benefit more than others, but the feature is worth enabling because it is a free settings change with no downside in most configurations. Modern graphics cards, such as the GeForce RTX 50 Series, are designed for PCI Express Gen 5, which provides the bandwidth that Resizable BAR takes advantage of, as described by NVIDIA.

The setting also contributes to a more balanced system. If you pair a strong processor with a graphics card that has generous VRAM, Resizable BAR helps the CPU hand off data without unnecessary waits. It is one of the first things to check when you want to get the most out of your hardware, alongside other settings like XMP profiles and hardware-accelerated GPU scheduling.

Requirements for Resizable BAR

Before enabling Resizable BAR, confirm that each component in the chain supports it. The CPU, the motherboard, and the graphics card must all be compatible, and the system must use a UEFI-based BIOS capable of exposing the option. Many recent processors have the required memory-mapping features, but support is not universal.

For AMD systems, this feature is often called Smart Access Memory and appears as a single toggle in the BIOS. On Intel systems, it is usually listed as Resizable BAR or Re-Size BAR Support. Both approaches rely on the same underlying PCIe mechanism.

You also need a reasonably modern operating system. Microsoft lists a compatible 64-bit processor, 4 GB of RAM, and a DirectX 12-capable graphics card as the minimum requirements for Windows 11. While Resizable BAR can work on Windows 10, Windows 11 includes optimizations for windowed games and other features that can further improve how the CPU and GPU communicate, as described by Microsoft.

Check your motherboard manual or the vendor's support page to see if the BIOS includes the required option. Many motherboards built for current-generation chips, such as those with Intel Core Ultra processors or AMD chipsets, provide it by default. If you are unsure, look for the setting after updating the BIOS to the latest version.

The graphics card also plays a role. NVIDIA's GeForce RTX 50 Series cards use PCI Express Gen 5, and all of them support Resizable BAR. Older cards may also support it, but you should verify with the card vendor's documentation. In general, any GPU released in the last few years that lists PCIe 4.0 or 5.0 support is likely to be compatible.

Step-by-step: how to enable Resizable BAR in the BIOS

The BIOS is the firmware that starts your system and configures hardware before Windows loads. To reach it, restart the PC and press the key that your motherboard uses, often Delete, F2, or F10, during the startup sequence. The exact key appears on the screen at boot or in the motherboard manual.

Once inside the BIOS, look for settings related to PCIe or graphics. The option may be under the Advanced menu, a PCI Subsystem Settings submenu, or a dedicated Graphics Configuration section. On AMD boards, it may be labeled Smart Access Memory. On Intel boards, it is usually called Resizable BAR or Re-Size BAR Support.

Before enabling Resizable BAR, you may also need to turn on Above 4G Decoding. This is a related PCIe setting that allows the system to map memory above the 4 GB boundary. On some motherboards, enabling Above 4G Decoding automatically reveals the Resizable BAR option, while on others you must toggle both separately.

After you find the option, set it to Enabled or Auto. Then save the changes and exit the BIOS. The system will reboot. If the setting does not appear, you may need to update the motherboard BIOS first. Many BIOS updates add Resizable BAR support and other stability fixes.

Some prebuilt gaming PCs come with Resizable BAR enabled out of the box, but it is still worth checking. If you bought a prebuilt gaming PC with a current processor and graphics card, the setting is often already active. You can confirm it by following the verification steps below.

• Restart the PC and press the BIOS key (Delete, F2, or F10) to enter the setup.
• Navigate to the Advanced or PCI Subsystem settings.
• Enable Above 4G Decoding if the option is present.
• Enable Resizable BAR or Smart Access Memory.
• Save and exit, then let Windows start normally.

Verifying Resizable BAR is on in Windows

After enabling the setting in the BIOS, you can check that it is active from Windows. One direct way is to open Task Manager, go to the Performance tab, and select the graphics processing unit (GPU). Look for a line that states "Resizable BAR" or "Re-BAR". If it says Yes or On, the feature is working.

Graphics card vendors also provide control panels that report the status. For example, NVIDIA's software shows the option under system information, and AMD's software lists it as a supported feature. These tools are official downloads and give the most reliable confirmation.

Another method is to use the Windows System Information app. Under Components, then Display, you can see the installed graphics adapter, though this view does not always include Resizable BAR status. For that reason, the Task Manager or vendor panel approach is simpler.

If the setting does not show as enabled, the cause is usually one of the requirements not being met. For instance, an old motherboard BIOS or a graphics card that lacks the feature can prevent the option from working even if it is turned on in the setup screen.

Common issues and how to resolve them

A missing Resizable BAR option in the BIOS is the most frequent problem. This usually means that the motherboard does not have the required UEFI firmware or that the CPU does not support the memory-mapping feature. Updating the BIOS to the latest version often adds the option, so that is the first step to try.

Another issue is that the option is present but the system becomes unstable after enabling it. In rare cases, a game may have a compatibility problem with Resizable BAR. If you see crashes or graphical glitches, you can disable the setting temporarily to see if it is the cause. The performance gain is not always large, so you may prefer to keep it off in that specific case.

Some graphics cards may not work with Resizable BAR until a firmware update is applied. Vendors occasionally release VBIOS updates that add support. Check your card vendor's official page for any such update, and apply it according to the instructions. This is a software-level change, not a hardware modification, so it does not require opening the machine.

Finally, verify that your Windows installation is current. Resizable BAR relies on driver support from the operating system. Installing the latest GPU drivers, as well as updating Windows itself, ensures that the feature is used correctly. The Windows 11 system requirements include a compatible graphics card and a 64-bit processor, both of which are necessary for this feature to work.

If you have followed these steps and the setting remains inactive, the most likely reason is that one piece of hardware is simply not compatible. In that case, you can still get most of the benefit from other optimizations, such as enabling XMP profiles for your memory or using PCIe 5.0 SSDs for faster loading.

Resizable BAR and choosing your next gaming PC

When you buy a gaming PC, either as a prebuilt or by selecting parts, Resizable BAR support is a good indicator that the system is modern. Current prebuilts from major builders include motherboards and graphics cards that support it, and many enable it by default. If you are comparing best 1440p gaming PCs or best 4K gaming PCs, check the product page or user manual for the phrase "Resizable BAR" or "Smart Access Memory".

For a system you plan to build yourself, the motherboard and graphics card must both support the feature. Look for a motherboard with a PCIe 4.0 or 5.0 slot and a graphics card from the current generation. The best gaming motherboards often list Resizable BAR support in their specifications, and current graphics cards are designed to take advantage of it.

It is also worth considering that Resizable BAR is part of a broader set of performance-related settings. Pairing it with a fast PCIe SSD, a capable processor, and adequate RAM gives you a balanced machine that can handle demanding games without a clear bottleneck. If you already own a gaming PC, you can enable it as described in this article; if you are shopping for one, prioritize a system that includes the feature.

Finally, remember that Resizable BAR is not a substitute for having enough graphics memory. Games with large textures benefit from both a high VRAM capacity and the ability of the CPU to access all of that memory. You can learn more about how much VRAM you need in the related guide on VRAM.

What to pick for your play

Questions

Is Resizable BAR safe to enable?

Yes, it is a standard PCIe feature that most modern systems support. The worst that can happen is a small performance difference or, in rare cases, an incompatible game that causes graphical issues. If that occurs, you can simply turn it off in the BIOS.

Does Resizable BAR affect the amount of VRAM available to games?

No, it does not change the VRAM capacity. It allows the CPU to access the full memory range, which can improve how efficiently the graphics card uses that memory. The total VRAM stays the same.

Do all games benefit from Resizable BAR?

Not all games show a benefit. Titles that load large textures or frequently stream assets can see a gain, while others may run the same. The feature is generally worth keeping on because it rarely causes a loss in performance.

Can I enable Resizable BAR on a laptop gaming PC?

Some gaming laptops support it, but the BIOS options on laptops are often limited. Check your laptop manufacturer's documentation for a setting called Resizable BAR or Smart Access Memory. If it is not listed, the feature is likely not available on that model.

Do I need Windows 11 to use Resizable BAR?

No, Windows 10 can also work, but Windows 11 includes additional optimizations for windowed games and improved graphics handling. As long as your system meets the basic Windows requirements, Resizable BAR will function on either version.