What GPU Shared Memory in BIOS Does to Your RAM
GPU shared memory in BIOS is a configuration where the integrated graphics processor reserves a fixed chunk of system RAM as its video memory, reducing the amount of usable memory available to the operating system and applications even when that integrated GPU is not actively used. On systems with 8GB or 16GB of RAM, this reserved pool can make a capable machine feel short on memory under everyday workloads. One MakeUseOf writer opened Task Manager and saw only 12.9GB of accessible RAM from a 16GB kit because the iGPU was holding a pre-allocated share. That reserved slice can range from 32MB to around 2GB, depending on motherboard and CPU settings. Understanding how this iGPU memory allocation works is the first step toward reclaiming system RAM and improving PC performance optimization without buying new hardware.
Check Your RAM and Confirm You Have a Dedicated GPU
Before changing BIOS settings, confirm that recovering GPU shared memory in BIOS will benefit your setup. Start in Task Manager’s Performance tab and compare installed RAM to “Available” memory; if the available figure is a gigabyte or more lower than expected, some of that gap may be reserved for integrated graphics and other hardware. Also confirm that your system has a dedicated graphics card. In Task Manager, Device Manager, or your GPU control panel, look for a discrete card listed on the PCIe bus in addition to any integrated graphics entry. If your display cable is plugged into the motherboard’s video output rather than the graphics card, your system likely relies on the iGPU and you should not disable it. This guide is aimed at users running their monitor from a discrete GPU who want to reclaim system RAM safely.
Enter BIOS and Find iGPU Memory Allocation Settings
To reclaim system RAM, you need to reach the firmware options where iGPU memory allocation is controlled. Restart your PC and repeatedly press Delete or F2 as soon as it begins to boot; most consumer motherboards use one of these keys to open BIOS. Look for menus named Advanced, Chipset Configuration, or Graphics Configuration, as many boards group GPU shared memory BIOS controls there. Inside, scan for settings labeled DVMT Pre-Allocated or UMA Frame Buffer Size. These options define how much RAM is reserved as shared graphics memory for the integrated GPU at all times. Interfaces differ by vendor, so the exact path may not match word-for-word, but anything referencing iGPU, shared memory, or frame buffer size is the area you need. Take note of the current value in case you want to restore it later.
Reduce or Disable GPU Shared Memory to Reclaim RAM
Once you locate DVMT Pre-Allocated or UMA Frame Buffer Size, you can reclaim system RAM by reducing the reserved pool to its minimum option, often 32MB or a similar low value. This keeps the iGPU available for emergencies while freeing most of the pre-allocated memory. If you always use a discrete GPU and do not plan to boot without it, you can go further. Set the primary display or Primary GPU to PCIe and disable any explicit Integrated Graphics option. According to MakeUseOf, disabling the iGPU freed about 1GB of RAM on a 16GB system, with typical gains ranging from 32MB to 2GB depending on configuration. Save and exit BIOS, then boot back into Windows and confirm that Task Manager now shows more usable memory under the Performance tab.
Know the Limits and Combine with Other RAM Tweaks
Even after trimming iGPU memory allocation, you may still see less usable RAM than the installed capacity. Some of this difference comes from the discrete GPU’s shared memory pool that drivers allocate dynamically, which you cannot disable, and from other hardware needs such as USB controllers, memory-mapped I/O, and driver overhead. That portion is required for stable operation. To squeeze more responsiveness from 8GB or 16GB systems, pair this BIOS tweak with software-side changes. Debloating Windows by disabling unneeded services can reduce background memory use, while tools like Microsoft’s RAMMap help examine and clear cached pages. For many users, freeing 1GB or more of reserved memory plus trimming background processes makes Windows 11 feel less constrained, especially when multitasking or gaming. If performance still falls short, consider that 16GB has become a practical baseline and plan upgrades accordingly.