I just opened 3 instances of sas on my pc (non-server) and each one
gratuitously hogged between 0.5 and 1.5mb of memory while doing absolutely
nothing, depending on whether the gui was visible or reduced, compared to a
single instance of word that efficiently used between 1 and 3.5mb ram.
Depending on how you've set up your sas profile it may or may not be locked
for each instance but generally you will be working from a temporary profile
on subsequent instances. In deciding this is the case SAS can freeze for
several seconds (the above 3 average 7 seconds each).
If your system can take the above performance hits then I see no reason not
to open multiple instances of sas.
If I start a job before finishing another I'll generally open a new instance
rather than create a new permanent library. This has the advantage of
keeping cleans logs and workspaces for each open job.
Having said all this, running concurrent jobs will come up against I/O, ram
and cpu issues in the same way running a single large job may. In such
circumstance a sas server is more suited than a puny laptop...
If you *cannot* open multiple instances then that is a separate issue that
someone else on the list will be able to assist with.