did you try PGDATA?
What OS are you using? Assuming you are on *nix you could put PGDATA on it's own partition. I did not have good experience with SSDs. Actually had one, it died so I went back to good old spinning HD.
We don't know what your database is doing and or where your performance issue lies. You give us no details about the size of your database, current configuration, performance requirements, etc etc etc...so the simple answer to your question is 'sure, why not'. SSD's are better (not to mention way cooler) in general than traditional platter drives but w/o knowing what you're doing or what you have, there's no right answer here.