1.7 KiB
1.7 KiB
BIOS VRAM Configuration — HP ZBook Ultra G1a
Why Change VRAM?
AMD Strix Halo uses unified memory — the CPU and GPU share the same physical RAM. By default, the HP ZBook allocates 32 GB as dedicated VRAM, permanently locking that memory away from the OS even when the GPU isn't using it.
AMD recommends keeping dedicated VRAM at 512 MB (minimum) and using GTT (Graphics Translation Table) for dynamic GPU memory access. With kernel boot parameters, the GPU can access up to ~60 GB on demand while the CPU retains full flexibility.
Current vs Optimal (64 GB system)
| Setting | Default | Optimal |
|---|---|---|
| Dedicated VRAM | 32 GB | 0.5 GB |
| GTT (dynamic) | ~15.5 GB | ~59 GB |
| OS visible RAM | ~31 GB | ~63.5 GB |
Steps
- Reboot the laptop
- Press F10 repeatedly during boot to enter BIOS Setup
- Navigate to: Advanced > Built-in Device Options (or Display section)
- Find: UMA Frame Buffer Size (may also be labeled "iGPU Memory" or "VRAM Size")
- Set to: 512 MB (or the smallest available option)
- Save and Exit (F10)
The exact menu path may vary by BIOS version. If you can't find it under "Built-in Device Options", check under "Advanced > Display" or "Chipset Configuration".
After BIOS Change
- Ensure kernel boot parameters are configured (run
make optimize-kernel) - Reboot
- Verify with
make audit:- VRAM should show ~0.5 GiB
- GTT should show ~59 GiB
- System RAM should show ~63.5 GiB