I am trying to work out possible bottlenecks in computer hardware. If you have a SSD as the OS drive will the only bottleneck when accessing images from another hard drive that is say HDD 7200RPM / USB2 etc the initial opening of the image/s. I take it that once an image file is open that all the work on this image will then be done on the fast SSD drive so you will be getting the fastest performance possible? Likewise, saving back to the "slower" device will be the only time that there is a bottleneck in speed?