Updating the graphics card won't do too much for Poser 5. Depending on your use of textures, lights and hair, adding RAM will be a better investment. Open the task manager while rendering and watch the memory values. If your computer starts swapping while rendering, more RAM will speed up rendering enormously. For speeding up the startup of Poser 5, don't use Don as default figure. Using a much simpler figure like the old school default guy will notably speed up loading.