Apple released spec benchmarks of its new G5 desktops. Claimed they were faster than a specific Dell system.
The same benchmark performed by the actual group that wrote the benchmark (not Dell) showed a much higher score than Apple demonstrated for the Dell.
The poor performance of the Dell under Apple's tests was because Apple did not use Intel's optimized and processor-tuned compiler for the pentium chip, instead using GCC.
Sources: Slashdot 1, Slashdot 2, Slashdot 3. Also see Apple's powermac site, and a detailed rebuttal.
As usual, the fine details are more exhaustively analyzed in the comment threads of the Slashdot posts than in the lede. But given Apple's history of deceit when it comes to speed claims (and their waffling marketing claims: Mhz matters! no it doesn't! yes it does!) it's unsurprising that Apple has no credibility whatsoever.
But what really is surprising is that Apple has returned to emphasize performance as a selling point for their machines, when all the most articulate defenders of the Mac have always been mor focused on software and OS (sadly, Brian is now also drinking the Kool-Aid with the usual "but they just wouldn't! they couldn't! they're Apple for god's sake!" true believer Jobs theology).
The most devastating argument against Apple's transparent attempt to recast their new desktops as superior to Intel rather than as an improvement over the G4 (which they assuredly are, and brilliantly so) is made by a great article in OS News:
I am not saying that G5 is slow. It is not! It is a fast machine. It is the product that has made Apple really caught up with the competition. But I don't see the dual G5 at 2 GHz overcoming the x86 today. Intel released today a 3.2 GHz P4 and they expect a new P4 version (faster core per same speed), to go all the way up to 4 GHz before the end of this year. Apple's roadmap is to reach 3 GHz in a year from now. So, has Apple caught up now for real, or Intel will speed through again and leave Apple in the same condition as it was until last Sunday night? We will know in a few months.
Apple's claim that the G5 is the "fastest desktop in the world" is false to begin with, but even more telling is that Apple's hardware moves forward in discrete steps whereas Intel is always evolving. Even if Apple could compete on speed, it coudl also never match PCs on price - which means that the only people buying these Macs for the speed will be those who already are drinking Kool Aid.
UPDATE: Now, THIS is why buying a Mac makes sense. THAT's the selling point - the kind of thing that makes an ambitious consumer think, "maybe I wouldn't mind dropping $1000 each for a few Powerbooks to act as terminals around the house someday."
It is inexplicable to me why Apple insists on screwing about with lies and statistics and stupid claims about performance when it has real value to offer consumers.