Mac OS X is slower than Mac OS 9 running on the same Apple hardware. But there are some reasons for that, Andrew Welch, president of Ambrosia Software,
explains in an online letter.
Why the performance hit? Welch says that there’s no single thing causing it, but that “in order to speed up OS X, a myriad of small tweaks and optimizations need to be made to every level of the operating system.”
“The way software development works is that you attempt to get something working first; you get it working fast second,” Welch said. “Optimization always takes place last; the reason for this is that you can’t accurately gauge what is causing your software to be slow (the bottlenecks) until the product is finished, and you’ve done some timing tests (known as profiling) to determine where your problem areas lie.”
Welch feels that Apple is working on the performance issue. And he adds that merely porting applications to the new Mac OS X application programming interfaces is not enough in terms of getting a decent performing product. Also, developers need to realize that the applications running on Mac OS X will be slower than the same applications running on OS 9 with some rare exceptions (“OpenGL performance seems better under OS X”).
“There are two main reasons for this: the first is that OS X is slower than OS 9, because it is a preemptive multitasking OS that was written to work first, it hasn’t yet been optimized, and because it uses a lot more memory than OS 9,” Welch explains. “The second reason is that the applications running on OS X have been written to work first (Mac OS developers are just getting up to speed writing apps for the new OS), and haven’t been optimized for OS X yet.”
He expects to see both situations change as Apple refines and optimizes OS X, and developers learn OS X and begin to do the same refinement and optimization with their applications. In his letter, Welch also talks about Carbon vs. Cocoa, Quartz, and the Mach scheduler. So what can you do to speed up OS X?
Welch says to get more RAM,
“a well-reasoned letter” and tell them that you consider the speed of Mac OS X to be a problem, and contact your favorite software vendors and tell them the same thing.
“I honestly believe that OS X is easier for newcomers and casual users to use than OS 8/9,” Welch concludes. “Experienced users will love the fact that there’s a command line there if they want it. If OS X can be sped up, I think Apple has a good chance of gaining customers rather than losing them to Windows. Here’s to hoping for speed.”