Re: (Solved) Leopard performance penalty (3x slower), NSPopAutoreleasePool

FROM : Gerd Knops
DATE : Sat Nov 17 21:38:11 2007

OK, color my face red... Xcode was responsible for the slowdown.

When testing on Leopard, I started my application through Xcode 
(normal run, not debug). Apparently that slows it down a lot...

Under Tiger I usually ran the App right from Texmate after an 
xcodebuild run, but sadly under Leopard xcodebuild is no longer usable 
(50 sec "checking dependencies"), so I started building and running 
the app through Xcode. I do not recall Tiger's Xcode slowing Apps down 
in a normal 'run', so that never occurred to me as the potential 
source of my troubles.

Gerd



On Nov 17, 2007, at 12:53 PM, Gerd Knops wrote:

> I have a complex Cocoa application, 10.4 SDK (no GC etc). Loading a 
> document (and performing a large number of calculations triggered by 
> that) takes 4 seconds under Tiger.
>
> Under Leopard, loading the same document takes 8 seconds until it 
> displays, after which the application is unresponsive for another 4 
> seconds, the entire time being spent in NSPopAutoreleasePool.
>
> I presume that performance penalty is largely due to Leopards more 
> complex memory handling. Has anybody else observed this, and knows 
> of any strategies to minimize that overhead?
>
> Thanks
>
> Gerd
>