November 1, 2001
From a performance standpoint, the main advantage
Mac OS X has over previous versions of the Mac OS, is the
ability to utilize the processor(s) more effecently. It does
this two ways. The first is a better multitasking
scheme, which allows you to run multiple applications, either
on one processor, or across multiple processors. The other
is more developed multithreading support. This allows retooled
applications to spawn multiple tasks that can run concurrently
on a single processors or, again, across multiple processors.
These abilities have been available in the Mac
OS for some time but only in a very limited and for the most
part inefficient way. Mac OS X releases these capabilities
as a matter of course, as far as Multitasking goes. Multithreading
becomes effective after a little programing effort on the
part of developers, to make their applications take advantage
This gives Mac OS X a great performance advantage,
but only to a certain point. Each individual Mac has only
so much processing power. Once you are utilizing it all, multitasking
or no multitasking, it won't process any faster. This is really
quite well demonstrated by the benchmark results below. In
the Fractal test, any available processing bandwidth is being
utilized by the program, under any OS. So OS X provides no
real benefit here. However in the QuikTime Sorenson encode
things become much more efficient when running under Mac OS
10.1. We are able to run two copies of QuickTime, with the
dual processors chomping away at data at the same time. The
result? A 90% efficiency improvement.
Below we compare performance when booted under
Mac OS 9.2.1, to 9.2.1 running applications in the Classic
environment, to straight on Mac OS 10.1.
All test were run on a dual processor G4/800
tower with 768 MB of RAM. Higher scores are better.
This test copies a single folder with several
This test copies a single large graphics
Here the dual processors are under-utilized.
Mac OS 9 and Classic lock up the machine until the encode
is done . Mac OS 10.1 is as fluid as mercury with about half
the processing power of the machine available to be utilized
for something else. It is up to you to make sure this potential
is not wasted.
For this test we ran two copies of QuickTime at once crunching
away on two files under Mac OS 10.1. Under Classic and 9.2 we
ran the QuickTime encode twice, one after the other .... because
we had to.
Crunch, crunch, crunch....
Processors are totally saturated under each