Question

Is it safe? For instance, if I create a bunch of different GCD queues that each compress (tar cvzf) some files, am I doing something wrong? Will the hard drive be destroyed?

Or does the system properly take care of such things?

Answer 1

If you take something that is normally IO limited, such as tar, and run a bunch of copies in GCD,

1. It will run more slowly because you are throwing more CPU at an IO-bound task, meaning the IO will be more scattered and there will be more of it at the same time,
2. No more than N tasks will run at a time, which is the point of GCD, so “a billion queue entries” and “ten queue entries” give you the same thing if you have less than 10 threads,
3. Your hard drive will be fine.