Macintosh share of the U.S. market tops 9%

Almost lost in the noise of the Presidential debates, the collapse of the Dow and the milling of those new MacBook aluminum unibodies were the preliminary reports from Gartner and IDC this week that showed sharp gains for Apple (AAPL) in third-quarter domestic computer shipments.

Apple’s unit shipments year-over-year grew 32% according to IDC, and 29.4% according to Gartner — more than six times the industry average.

As Gartner measures it, Apple’s market share hit a record 9.5% in calendar Q3, up from 7.7% in the same quarter a year ago.

IDC’s numbers show even steeper gains: it puts Apple’s Q3 market share at 9.1%, up from 7.3% in 2007.

It’s almost as if Apple were in a different business than Dell (DELL), HP (HPQ), Acer and Toshiba. While the average selling price of PCs continued to drop this summer — thanks, as Gartner notes, to the growing popularity of under-$500 “netbooks” — Apple kept its prices high as it added memory, power and stylish features.

Exactly how profitable calendar Q3 (Apple’s fiscal Q4) was for the company we’ll find out at the close of market next Tuesday, when Apple issues its quarterly and annual earnings reports.

Below: the raw data from Gartner and IDC. Note that neither company reports Apple’s worldwide sales numbers.

[Gartner chart courtesy of AppleInsider.]

[IDC chart courtest of Electronista.]

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