What GPU Shared Memory Is and Why It Eats Your RAM
GPU shared memory in BIOS is a setting that reserves a fixed chunk of your system RAM as video memory for the CPU’s integrated graphics, even when you have a dedicated graphics card installed and doing all the rendering work, which leaves less usable RAM for Windows, games, and applications and can make a 16GB system behave more like it only has 12–13GB available under heavier multitasking loads. Integrated GPUs do not have their own VRAM, so they borrow from system memory. The problem is that many boards reserve this memory by default, regardless of whether the iGPU is actually in use. One MakeUseOf writer opened Task Manager on a 16GB machine and saw that “only 12.9GB of the total RAM was accessible,” with the rest locked away for the iGPU. Freeing this pool can instantly give your system more headroom.
Check Your RAM Availability Before Tweaking BIOS
Before changing any GPU shared memory BIOS options, confirm that RAM is really being reserved. Open Task Manager (Ctrl + Shift + Esc), go to the Performance tab, and select Memory. Compare Installed, Hardware Reserved, and In Use. If you see a large Hardware Reserved value on a system with an integrated GPU, that chunk is likely tied to iGPU memory allocation. The higher Windows 11 overhead and more background services make this loss more noticeable when you only have 16GB. Heavy multitasking, Chrome tabs, and games can push memory usage close to the limit, leading to stutters or slow app switching. If you use a discrete GPU for all displays and gaming, this reserved pool often provides no benefit. Once you confirm a sizable hardware reservation and that your monitors are connected to the discrete GPU, you are ready to free up system RAM in BIOS.
Enter BIOS and Find the iGPU Memory Settings
To start this BIOS optimization guide, reboot your PC and press Delete or F2 repeatedly as it starts to open the firmware interface. On many modern boards you may need to switch from Easy/Basic mode to Advanced mode, often with an F7 key, to see deeper chipset and graphics options. Motherboard menus vary, but the path is usually something like Advanced → Chipset Configuration or Advanced → Graphics Configuration. You are looking for options that describe iGPU memory, such as DVMT Pre-Allocated on Intel systems or UMA Frame Buffer Size on many AMD platforms. These control how much RAM is carved out as dedicated graphics memory for the integrated GPU. Remember that naming conventions differ between vendors, so take your time and do not change unrelated options. If unsure, note the current values so you can restore them later if needed.
Reduce or Disable iGPU Memory Allocation to Free Up RAM
Once in the graphics or chipset menu, you have two main ways to free up system RAM: lower the iGPU memory reservation or disable the iGPU entirely. To disable iGPU memory allocation while keeping a fallback, set DVMT Pre-Allocated or UMA Frame Buffer Size to the smallest value available. This minimizes the hardware-reserved pool while still allowing the iGPU to function in emergencies. If you never plan to use integrated graphics and always run a discrete card, you can go further. Set the Primary GPU option to PCIe, or disable integrated graphics if a toggle exists. This prevents the firmware from reserving memory for the iGPU at all, but your system will not display video without the discrete card installed. After making changes, save and exit BIOS. Back in Windows, check Task Manager again to see how much RAM you have reclaimed.
What Performance Gains to Expect and When to Keep iGPU On
The performance boost from disabling GPU shared memory depends on how memory-bound your workload is. If your usual usage keeps RAM far below capacity, you may not notice a big difference. But when your system hovers near the limit—many browser tabs, game launchers, background tools—having another gigabyte or more free can smooth out stutters and reduce swapping to disk. This tweak pairs well with other BIOS improvements such as enabling XMP or EXPO profiles so your RAM runs at its advertised speed instead of base JEDEC values. Some users describe their PCs as feeling “brand new without a hardware upgrade” after tuning memory and related settings. Keep a small iGPU allocation if you sometimes need to boot without the discrete GPU, or if you use features that rely on integrated graphics. Otherwise, reclaim that RAM and let your dedicated card handle the graphics work.