Proxmox virtio GPU on Windows 10 is slow because there’s no 2D acceleration. QXL has it. Here’s the benchmark and the fix.
The Benchmark
I tested both display adapters on the same Windows 10 VM. QXL scored 60 fps in the 2D benchmark. Virtio-GPU got 15 fps. That’s a 4x difference. The reason is simple: QXL has a 2D acceleration driver for Windows. Virtio-GPU doesn’t. It falls back to an unaccelerated framebuffer.
Why Virtio-GPU Is Slow
Virtio-GPU is designed for 3D acceleration with virgl. On Linux guests, it works okay. On Windows, there’s no virgl driver. So you get no 3D acceleration. And no 2D acceleration either. The Windows virtio-gpu driver just presents a dumb framebuffer. Every pixel is drawn by the CPU. That’s slow.
QXL, on the other hand, has a proper Windows driver. It offloads 2D operations to the host. Things like moving windows, scrolling, and video playback are much smoother. The driver is mature. It’s been around since the SPICE days.
The Fix
Just switch the display adapter to QXL. In the VM’s hardware settings, set Display to qxl. That’s it. No driver installation needed. Windows will automatically use the QXL driver. If you need better performance, install the SPICE guest tools. They include the QXL driver and improve clipboard sharing.
For 3D workloads, you’d need GPU passthrough or a vGPU. But for a desktop VM, QXL is the way to go. It’s what Proxmox recommends for Windows. Now you know why.
If you’re messing with VM display settings, you might also run into the secure boot greyed out issue. Different problem, same kind of annoyance.
