Reports: Apple is No. 3 PC maker in U.S., No. 6 worldwide by Philip Elmer-DeWitt @FortuneMagazine July 17, 2008, 11:07 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Dueling reports Wednesday from the two leading PC survey firms — Gartner and IDC — confirm what the crowds at the Apple AAPL stores have been telling us: The Mac had a great second quarter. According to Gartner, Mac sales grew 38% year-over-year to edge out Acer/Gateway/PackardBell for the No. 3 spot in the United States after Dell DELL and HP HPQ . IDC recorded slightly slower growth (31.7%) and has Apple still trailing Acer by 2,000 units — not a statistically significant figure in a quarter in which Apple shipped an estimated 2.37 million Macs worldwide. Gartner puts Apple’s U.S. market share at 8.5%, up from 6.4% a year ago; IDC has it at 7.8%, up from 6.2%. Both reports are preliminary. Apple still doesn’t make the top 5 in either company’s list of top PC vendors worldwide, although IDC’s Loren Loverde says it came in No. 6. (link) It’s worth noting that while its competitors were cutting prices to boost sales in a tight domestic economy, Apple managed to grow faster while maintaining profit margins that are the envy of the industry. And if you count iPhones and iPod touches as computers, says 9to5 Mac‘s Seth Weintraub, “you get a whole new ball game.” Below the fold: the charts from both reports. Gartner charts courtesy of AppleInsider.