Hey,

I'm running a bare metal NT 3.1 system for some OS archeology with the vbemp miniport driver for high resolution and color depth, but without hardware acceleration due to it using the VESA Bios Extensions. Rendering on high resolutions, particularly scrolling in text editors and console windows, was painfully slow. That's why I modified the framebuf display driver (sources are part of the NT 3.1 DDK) and added a shadow framebuffer as some sort of caching layer to speed up rendering operations that attempt to read video memory (DrvCopyBits, DrvBitBlt et al). So far, I'm satisfied with the perceived performance improvement and decided to open source the driver at nt31-shadowbuf. A before/after screencap and precompiled binaries are part of the repository. Please note that VMs won't really profit from shadow buffering, because memory access times of virtual hardware don't diverge as much as with real hardware.

PS: The author of vbemp also released a display driver called "FRAMEVBE" with the same intention, but it isn't available for NT 3.1.

Maybe someone finds this useful, I'm interested in feedback how this performs on other systems.