The MaraThon Racer is a cheap way to get more performance from a Mac II. It supplies a cache of 32K of high-speed static RAM that increases performance an average of 15 percent. Excel spreadsheet recalcs speed up about 20 percent, but 4D sorts don’t show much improvement. Most applications fall between those extremes. The Racer can be somewhat difficult to install; the 68020 chip must be moved.