Using a machine on a direct connection to a machine with a scratch area is the next best choice as far as processing speed is concerned. The slowest rout is over our campus internetwork. The campus is made up of many separate networks joined by routers. The addition of a router further slows the rate of data movement from a scratch area to and from a machine doing work on that data. The location of your data should depend primarily on the processing location.
Processing puts the biggest demand on the speed of data access.
If, for example, you have some data which you wish to display and then process, the choice of scratch area should be based on the processing needs as this is more intensive that displaying data. Not all operations on your data are as intensive as processing. Some activities such as moving your data to or from tape can benefit from the global accessibility of the various scratch areas. Several scratch areas are available under different names at both PUCC and here in Biology. Although the path names are different, they refer to the same piece of disk space.