Question

I have been trying to read up on GCD and trying to figure it out. I read a lot of places, that one should always use GCD, if one is doing some heavy work, which will freeze up the UI, and I do understand that, but could GCD also be used just for performance sake. Say I have a loop that need to run 10 times, each iteration being data heavy. Would it improve performance to run half of these iterations of a different thread, so that two threads are sharing the workload or will it still take the same amount of time to go through the loop?

Answer 1

It would help running two serial gdc queues if your device has two processors. However, the idea is that you shouldn’t care, call dispatch_queue_create with DISPATCH_QUEUE_CONCURRENT and let the device figure out what is the optimum number of tasks to run in parallel.