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The shorter general queues have higher priority and automatic queue selection will put your job in the shortest compatible queue. If you use a dedicated (non-general) queue in your production environment, continue to specify the queue in your bsub command but just add the '-W' option.
By supplying a RUNLIMIT, your jobs can start faster because they stand a better chance of using a feature called "backfill". An increasing number of users are now running large parallel jobs across multiple cores/slots. These parallel jobs can take a considerable amount of time to reserve all the cores they need to start. The scheduler will attempt to backfill (run smaller jobs on reserved cores) as long as the estimated start time of the bigger parallel job is not affected.
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