In what seems to be a reaction to feedback about his recent .plan update about Macintoshes, John Carmack made another large update to his .plan on the Mac, discussing the source of the performance figures he mentioned, and clarifying what he meant about the Mac OS. Here's a chunk of the large update:

...So, clearly, hand tuned asm code can make either platform pull ahead. It also shows that the two platforms are at least fairly close in performance. I never said macs were SLOW, just not quite as fast as the best intel systems.

Quake3 doesn't software rasterize, so there isn't any great place for lots of asm code (the great place is in the OpenGL driver). The code is essentially identical on all platforms.

Q3 is definitely faster on a wintel system than a macos system. When the wintel version is released, everyone will be independantly repeating that measurement.

Even this measurement isn't exactly an apples to apples comparison, because the OpenGL driver and 3D card are still a significant variance. The two can be broken out farther: Q3 can be run without 3D output to test just the identical compiled code. Wintel is still faster, although somewhat less so...

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"Sucks" is a subjective description that can be dismissed as opinion. Note that I have NEVER said that the hardware sucks, or the user interface sucks, just that the mac OPERATING SYSTEM sucks.

"Faster", when qualified with testing conditions, is objective, and all the wishing in the world doesn't change it.

Objectivity and quantification are the paths to improvement.

I will be very happy if Apple can produce a desktop system that is faster than anything else you can get. I respect good engineering from any source. Altivec should be better than the PIII extensions (trinary ops -- yeah!). The upcoming system architectures look good. They have a shot at it, but they won't make it if they complacently think "oh, we are already faster than any pc system".

My twin turbo F50 can still be outrun at the dragstrip by much cheaper race cars. Many ferrari owners would not dare set foot at a drag strip, because they fear objective measurements that may not show their important possession in the best light. I would rather have the facts, so I can base future decisions on logical grounds.