What Is Resizable BAR and Does a Gaming Laptop Need It?

What Is Resizable BAR?

Resizable BAR (Base Address Register) is a technology that allows the CPU to access the entire graphics memory of the graphics card at once. Traditionally, the CPU could only access a small portion of the VRAM at a time, which could limit performance in certain scenarios. With Resizable BAR, the CPU can read and write to the full VRAM, reducing communication delays and potentially improving performance.

This technology is particularly relevant for gaming laptops because the CPU and GPU are tightly integrated in a compact chassis. By enabling the CPU to access more VRAM, Resizable BAR can help reduce bottlenecks, especially in games that are CPU-intensive or that frequently access large textures and assets. To understand the role of VRAM in gaming, see our explanation of graphics memory.

How Resizable BAR Works

In a system without Resizable BAR, the CPU communicates with the GPU through a limited window of memory. This means that when the CPU needs to access data stored in VRAM, it has to request small chunks at a time, which can create delays. Resizable BAR expands this window, allowing the CPU to access the full VRAM capacity directly.

This is made possible through the PCI Express (PCIe) interface, which supports larger memory access requests. When both the CPU and GPU support Resizable BAR, and the system BIOS is configured to enable it, the CPU can efficiently manage the GPU's memory, leading to smoother data flow and potentially higher frame rates. For more on how PCIe generations affect gaming laptops, check our PCIe Gen4 vs Gen5 guide.

Does Resizable BAR Improve Gaming Performance?

Resizable BAR can improve gaming performance, but the impact varies depending on the game and the hardware. In some titles, enabling Resizable BAR can lead to noticeable gains in frame rates, especially at lower resolutions where the CPU is more likely to be a bottleneck. In other games, the improvement may be minimal or negligible.

The technology is most beneficial in games that are CPU-bound or that rely heavily on large texture files. By allowing the CPU to access more VRAM, Resizable BAR can reduce stuttering and improve overall responsiveness. However, it is not a magic solution; the actual performance gain depends on how well the game is optimized for this feature. If you are also considering other performance-enhancing technologies, our DLSS explainer might be helpful.

Compatibility and Requirements

For Resizable BAR to work, several components must support it: the CPU, the GPU, and the system BIOS. Most modern processors from Intel and AMD support Resizable BAR, as do recent graphics cards from NVIDIA and AMD. However, support can vary by generation and model, so it is important to check the specifications of the laptop.

On many gaming laptops, Resizable BAR is enabled by default, but on some, it may need to be turned on in the BIOS settings. The exact steps to enable it can vary by manufacturer, so it is advisable to consult the laptop's manual or the manufacturer's website for instructions. Some laptops may also require a BIOS update to enable Resizable BAR support. For guidance on updating BIOS and drivers, see our how-to article.

Should You Care About Resizable BAR?

For most gamers, Resizable BAR is a nice-to-have feature rather than a must-have. If you are buying a new gaming laptop, it is likely that the system already supports Resizable BAR, and it may be enabled by default. If you are considering an older model, you may want to check whether it supports this technology and whether it can be enabled.

If you play games that are CPU-intensive or that benefit from faster VRAM access, Resizable BAR could provide a small performance boost. However, the impact is often modest, and other factors such as the GPU model, VRAM capacity, and CPU performance will have a much larger effect on your gaming experience. When choosing a new laptop, you can rely on our best gaming laptops list for systems that already include this feature.

How to Check if Your Laptop Supports Resizable BAR

To check if your gaming laptop supports Resizable BAR, you can look at the specifications provided by the manufacturer. Many manufacturers list Resizable BAR support in the technical specifications of their laptops. You can also check the BIOS settings to see if there is an option to enable or disable Resizable BAR.

If you are unsure, you can consult the laptop's manual or contact the manufacturer's support. Additionally, you can use system information tools to check the PCIe capabilities of your system. However, the most reliable way is to check the official specifications from the laptop maker. For a deeper look at CPU and GPU compatibility, you might find our Intel vs AMD CPU guide and laptop GPU model numbers useful.

What to pick for your play

Questions

What does Resizable BAR do?

Resizable BAR allows the CPU to access the full graphics memory of the GPU at once, instead of in small chunks. This can reduce communication delays and potentially improve gaming performance. For more on VRAM, see our VRAM explainer.

Is Resizable BAR the same as Smart Access Memory?

Smart Access Memory (SAM) is AMD's implementation of Resizable BAR. Both technologies work similarly, but SAM is specifically optimized for AMD CPUs and GPUs. Check our AMD Advantage guide for related information.

Does Resizable BAR work on all gaming laptops?

No, Resizable BAR requires support from the CPU, GPU, and BIOS. Most modern gaming laptops support it, but older models may not. Check the specifications of your laptop to confirm. You can also look at our best esports gaming laptops for models that typically include this feature.

Can I enable Resizable BAR on my laptop?

If your laptop supports Resizable BAR, you can enable it in the BIOS settings. The exact steps vary by manufacturer, so consult the laptop's manual or the manufacturer's website for instructions. Our BIOS update guide might help.

Will Resizable BAR improve FPS in all games?

No, the impact of Resizable BAR varies by game. Some games may see a noticeable improvement, while others may see little to no change. It is most beneficial in CPU-bound games or those that use large textures. For a broader view of performance features, read about NVIDIA Reflex.