Virtual PC and video ram

Virtual PC emulates an S3 Trio 64 Video card with 8mb of video ram (VRAM).  From time to time I get people asking me why we do not increase the amount of VRAM – and there are a couple of reasons why:

  1. VRAM is a fixed overhead.  Each virtual machine that you launch uses 8mb of your computers memory to store our VRAM information.  If we increase this – it will increase the amount of memory used for each virtual machine – whether the virtual machine is using this extra memory or not.

  2. On video cards with hardware 3D acceleration support VRAM is used for storage of textures, and other performance improving measures.  However with a 2D video card VRAM is only used to store a single frame buffer of the contents on screen.  This means that with a 2D video card (such as we emulate) adding more VRAM just allows you to support higher resolutions – but it does not provide better performance.  At 8mb we are able to display at up to 1600×1200 resolutions.