Not really a question, just sharing something I just found an answer to.

Hope no-one minds me posting this here.

If it's been posted before - apologies.

My laptop has been spawning a process called QuickLookSatellite-legacy. This process - sometimes more than one instance - impedes my system's performance dramatically. The first clue it's running is when the cooling fan goes nuts. It's about the only time I hear my fan.

I eventually tracked down a post on the apple forums that describes, identifies the cause and cures the problem.

Most people seem to have deleted the offending file, I just renamed it in-situ.

The file is in this location /Applications/DraftSight/Contents/Library/Quicklook and is called "FxQuickLookDrawing.qlgenerator" 

After renaming this file, my problem is gone. It appears not to be overly important, the clue is in the name :)

Hope this is useful,

Regards