On 01 May 2015, at 06:46, Graham Cox <graham....@bigpond.com> wrote: > I use NSOperationQueue with the default -maxConcurrentOperationCount which is > NSOperationQueueDefaultMaxConcurrentOperationCount, i.e. let the system > figure it out. That appears to create 4 threads for my particular machine, > which has a Core i3 (2 cores) CPU. My peak CPU usage is reported as 418%. I’m > not sure how it achieves that from a dual core CPU, but one would assume that > Apple know what they’re doing [/irony].
Does your Core i3 do HyperThreading? In that case, there are a second set of virtual CPUs, so that when one blocks, a second thread can get swapped in *at the hardware level* and get cycles. Cheers, -- Uli Kusterer “The Witnesses of TeachText are everywhere...” http://zathras.de _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
