This surface is rather slow in both generation and display for systems over several hundred atoms. The SURF calculation is quite exact and will show complete detail even when it isn't needed. The use of disk space as an interprocess communications medium takes up about half of the run time.
There is an environment variable which can affect the Surf display option:
A helpful trick when constructing surfaces is to use the Apply Changes Automatically toggle button on the graphics window wisely. That is, since surfaces often take a long time to build, changing viewing parameters such as the probe radius can cause long delays. By default, each time you hit the probe radius button, VMD rebuilds the surface. If you want to reduce or enlarge the probe radius by several increments, then you would end up rebuilding the surface multiple times. By toggling the afore-mentioned button, you can force VMD to update on your command only. This trick is sometimes helpful with other representations as well.
For a much faster surface rendering method, see the descriptions of `MSMS'. `QuickSurf'.