A few things: - The little ARM in the iPad 3 is nothing compared to your desktop. Not only is it not as fast, it doesn't have the memory bandwidth. Also, an iPad 4 will be twice as fast. - make sure you're running optimized code. You can set optimization flags on individual files (that's what I do in our compute-heavy code, so I can run debug releases for the UI but leave the computation optimized). - Find a way to compute less. Algorithmic optimizations are key here. Maybe a larger step size? - Can you break up the work into multiple tasks? That will allow you to parallelize the work. At the very least, make sure you're doing it on a separate dispatch queue/NSOperationQueue so it doesn't block your main UI.
On Aug 7, 2013, at 13:50 , Trygve Inda <[email protected]> wrote: > I have an app that is running slow. I have narrowed it down to several > functions which are trig-intensive (used to calculate the position of the > moon at a given moment and more specifically to calculate rise/set times). > > To calculate the position and rise/set times for a month on average, > requires: > > 300 trig functions for position > 24 points in time to find the correct set of three points > 30 days > 2 events > > Total of 432,000 trig functions (mostly sin and cos) > > On my iPad 3, this takes about 3 seconds, and on my desktop (2.3GHz > Quad-core i7) it is nearly instantaneous. > > I am using doubles (not floats). > > What can I do to speed this up? > > > > _______________________________________________ > > Cocoa-dev mailing list ([email protected]) > > 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/rmann%40latencyzero.com > > This email sent to [email protected] -- Rick _______________________________________________ Cocoa-dev mailing list ([email protected]) 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 [email protected]
