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.

Microsoft (MSFT) Windows continued its downward drift and Apple’s (AAPL) Mac OS X inched up to a record 7.95% in the market share survey issued Tuesday by Aliso Viejo, Calif.-based Net Applications.

The biggest gain, however, was recorded by the open-source operating system Linux, which jumped more than 16% in June — albeit from a small base — to hit 0.79%.

The iPhone held steady at 0.16%, reflecting a leveling off of what had been double-digit growth as buyers waited for the new iPhone 3G, which goes on sale next week. In a separate survey issued Monday, RBC Capital reported “unprecedented pent-up demand” for the new model. Data taken from 3,600 members in RBC’s Technology Adoption Panel in early June showed that 56% of those planning to buy a smartphone in the next 90 days planned to buy an iPhone — up from 35% in March and more than double the interest in any of the other brands surveyed. See here for more detail.

The monthly Net Applications survey is conducted by sampling browser data from some 160 million visits to websites operated by the firm’s clients. Although it describes the results as “market share,” Net Applications does not actually measure share of market in the traditional sense by revenue or unit sales. It does, however, provide a consistent methodology by which to measure operating system trends.

To see their July 1 report, click here. The results are summarized in the table below.

Drilling deeper into the numbers, ArsTechnica’s Charles Jade notes that the numbers for Intel Macs grew by a quarter of a percent to 5.26 percent, while PPC Mac’s declined to 2.7 percent. In other words, Intel Macs increased at twice the pace of decline for PPCs. “The rapid decline of PPC Macs coupled with sharp gains for Intel Macs no doubt factored into the decision to make Snow Leopard Intel only,” Jade speculates. His chart below:

UPDATE: Net Applications’ model must be more dynamic than we knew. At sunrise in New York on Monday, Mac’s June share was 7.95%. By 8:30 a.m. CT, when Jade posted his report, it had risen to 7.96%. By 3:00 a.m. ET Tuesday it had dropped to 7.94%. And these are last month’s numbers!

After drifting inexplicably in February, March and April — actually losing market share in two out of three months just when Macintosh sales seemed to be on fire — Mac OS X recovered smartly in the Net Applications survey issued overnight Sunday.

Apple’s (AAPL) share of the operating system market grew 5.69% in May to hit a record 7.80%, while Windows in all its flavors dropped half a point to 91.17%. That’s a record low for Microsoft (MSFT), which nonetheless still runs on 9 out of 10 computers on the Internet, as Net Applications measures it (more on its methodology below).

The iPhone’s OS market share, whch Net Applications measures separately from OS X, has temporarily leveled off, according to the report, reflecting the shortage of product as Apple cleared inventory in May and customers held off purchases in anticipation of the new 3G model. In an IDC report issued Friday, the iPhone actually lost share in the smartphone market, falling from 26.7% in the last quarter of 2007 to 19.2% in the first quarter of 2008. RIM (RIMM), meanwhile, gained share in the same period, growing from 35.1% to 44.5% on the strength of new, consumer-oriented BlackBerries. (see here)

The discrepancy between IDC’s and NetApplication’s numbers can be explained to some extent by the nature of the two surveys. IDC’s quarterly reports are sales counts, based on surveys of retail outlets. Net Applications, by contrast, collects data from the browsers of visitors — some 160 million per month — to its customers websites. As such, its findings are probably better described as a snapshot of installed base taken from a less-than-random sample. But the results are useful for indicating trends, and tend to correspond well to domestic market share as measured by more traditional methods.

To see Net Application’s June 1 report, click here. The results are summarized in the table below:

Subscribers: to see the chart, click here.

Here’s a new way to slice Apple’s growing share of the computer market.

Last March, the NPD Group reported that Apple’s retail market share — its cut of the computers sold in brick-and-mortar stores — had climbed to 14%, a figure that’s roughly double its overall share of the U.S. market and reflects the power of the Apple Store to draw customers and move product.

What NPD didn’t report at the time was the huge growth in Apple’s share of the so-called “premium” computer market — machines that cost more than $1,000.

To some extent, Apple’s (AAPL) share of this market is growing by default. Companies like HP (HPQ), Dell (DELL) and Lenovo ship enormous quantities of PCs at price points between $500 and $750, whereas the only Macintosh that sells for less than $1,000 is the $599 Mini.

Still, Apple’s share of the $1,000-plus retail market was less than 18% in January 2006 according to NPD. By September 2007, it had grown to more than 57%. And in the first quarter of 2008 it hit a record 66%.

This nugget of retail data comes from Joe Willcox, who writes the Apple Watch column for eWeek (see here). He extracted it from an interview last Friday with Stephen Baker, NPD’s vice president of industry analysis.

“Apple has got better distribution than it’s had in the last 15 years,” Baker told Willcox. “They’re in the right spot right now.”

It doesn’t hurt Apple that once you’re in its store, you can’t buy any computer with a screen for less than a grand. “If you don’t give people a choice,” Baker said, “people will spend more.”

[Chart courtesy of eWeek.]

On March 18, along with the latest version of iTunes and QuickTime, Apple slipped a copy of Safari 3.1 into the Software Update it sent to millions of Windows users — even though strictly speaking the first non-beta version of Safari for Windows was a new program and not an “update.”

Critics, among them longtime Apple supporters, excoriated the company for what was widely viewed as an uncharacteristic sleight of hand. They called it “disgraceful,” “malware” and a violation of the “trust relationship great companies have with their customers.” (See for example here)

What they didn’t call it was effective. But data released on Thursday by Net Applications show that the brief experiment worked rather well. During the month that it lasted, the percentage of Safari for Windows users among Net Applications’ clients, which had never climbed above .07%, grew three-fold, to .21%.

It might also have helped that the program was getting good reviews, although it’s not clear how many Microsoft (MSFT) Windows users would ever have tried Apple’s (AAPL) Web browser if it hadn’t been shoved in their face.

On April 18, Apple revised its Software Update protocol. New programs are now clearly marked as such and the box to accept them is unchecked by default.

The iPhone gets the most press and the iPod sells in the largest quantities, but it’s the Macintosh that really drives Apple’s growth, says Gene Munster.

In the second installment of a multipart report on Apple’s “3 Cylinder Engine,” Piper Jaffray’s chief Apple (AAPL) analyst looks at the Mac business over the next couple of years and likes what he sees. In particular:

• Growth: After Apple introduced the Intel Macs, Mac sales grew 37% in 2007, more than double the industry-wide rate of 15%. Munster is modeling 2.0 to 2.1 million Macs for the March quarter (vs. the Street’s 1.95 million). He believes Apple will continue to outpace its competitors with upgraded iMacs and Mac minis in the next 3 months and redesigned MacBooks and MacBook Pros in time for the ‘08 education season.
• Market Share: According to IDC, Apple’s worldwide market share grew from 2.4% in 2006 to 2.9% in 2007. (See chart below.) Munster is conservatively modeling global market share to remain flat this year, but he notes that enterprise sales account for 70% of the worldwide market, a segment Apple is not aggressively targeting. In the consumer market, where Apple does compete, he estimates the Mac’s share is now 10% worldwide and an impressive 21% in the U.S.
• Sales Price: While Apple has gained market share over the past three years, it has also been able to resist the industry trend of decreasing sales prices. In fact, it actually increased its average sales price (ASP) by more than $150 from December ‘05 to December ‘07. “The combination of increasing ASPs and rising market share is evidence of a compelling product line,” writes Munster.

One more thing: although consumers and investors tend to believe Macs cost 20% to 30% more than comparable PCs, according to Munster, he did some price comparisons and found that on average, the price difference is closer to 16% for desktop machines and 9% for laptops — essentially unchanged from a similar comparison he made two years ago. Details in the charts below the fold.

After showing impressive gains in December and January, Mac OS X’s slice shrank a bit last month in the latest Net Applications survey of operating system market share. The iPhone’s share growth, meanwhile, continues to outpace every other category except “Other.”

As Net Applications measures it (more on its quirky methodology below), the Mac’s market share dipped to 7.46 percent, 1.45 percent off its January record high. Apple’s (AAPL) iPhone, meanwhile, hit 0.15 percent, a personal best, up 7.69 percent from January.

Microsoft (MSFT) Windows in all its flavors continues to dominate, with a 91.58 percent share, up a hair for the month but still off the 93.3 percent it held a year ago.

Net Applications’ monthly surveys sample data from visitors to some 40,000 websites operated by the firm’s clients. As such, the findings are a snapshot of installed base — with a bias toward machines that spend a lot of time on the Net — rather than a month-to-month measure of computer systems sold. The February results are summarized in the table below. The full report can be viewed here.

Good things come to those who wait.

Steve Jobs may have disappointed his fan base — and Wall Street — by not having more to offer at Macworld last month. But whether by design or by way of compensation, the folks at Apple (AAPL) have been extra busy in the weeks since.

Last week the company released the new 16 GB iPhone that many Apple watchers had expected to see at Macworld, as well as the 32 GB iPod touch that most had not.

Yesterday it released a major update to Mac OS X Leopard that fixed a slew of bugs and made some cosmetic changes (especially in the dock and stacks) that users had been begging for.

Today we got a two-fer:

• Aperture 2, a major upgrade of Apple’s high-end photo editing and management software, a favorite with professional photographers, and
• Apple TV “Take 2“, the free upgrade that allows movie rentals and direct downloads from the iTunes store. Jobs had promised that it would be available within two weeks of Macworld. It arrived in four.

What’s next? Rumors abound that there will be an Apple event before the end of the month at which the company could reveal everything from the iPhone software developers kit promised for February (but also rumored to be delayed) to $100 price cuts in the iPhone and iPod touch lines.

The news was almost lost yesterday in the Microhoo hoopla: even as Microsoft (MSFT) was trying to buy its way into some kind of parity with Google (GOOG) by gobbling up Yahoo (YHOO), a new survey showed that Apple (AAPL) had taken another little bite out of Redmond’s core business.

According to the latest market share data from Net Applications, Mac OS X’s slice of the computer operating system market grew 3.56% in January while Microsoft Windows’ dropped .36%.

As Net Applications measures it (more on its methodology below), the Mac’s market share stands at a record 7.57%, up 21.7% from Jan. 2007.

“Apple’s market share gains in December for the Mac and iPhone are impressive,” the report concludes. “However, for the last days of December, the numbers are nothing short of spectacular.”

The really good news for Apple, according to Net Applications, came in the last two days of the month, when Mac OS X hit 8.01%.

Windows is still dominates the desktop, of course, with a 91.46% share, but that’s down from 93.33% a year earlier.

Net Applications’ monthly surveys sample data from visitors to some 40,000 websites operated by the firm’s clients. As such, the findings are a snapshot of installed base rather than a month-to-month measure of computer systems sold. The January results are summarized in the table below. The full report can be viewed here.

Acer, the Taiwanese computer manufacturer that acquired Gateway Inc. last year, has as a result overtaken Apple (AAPL) in both U.S. and worldwide computer sales, according to preliminary reports issued Wednesday by Gartner and IDC.

Although the two market research firms show Apple’s domestic computer sales in the Christmas quarter up roughly 30 percent from last year — outpacing the industry average by better than 3 to 1 — Apple’s share of the market actually fell during those three months. According to Gartner, the Mac now has 6.1 percent of the U.S. market; according to IDC it’s 5.7 percent. That puts Apple in 4th place behind Dell (DELL), HP (HPQ) and Acer in U.S. personal computer sales.

In October, Gartner and IDC estimated Apple’s 3Q share of the U.S. market to be considerably higher: 8.1 percent and 6.3 percent, respectively. See here.

In worldwide PC sales, Apple doesn’t make the top five in either research firm’s report.

These results would seem to contradict analysts’ predictions of blowout Christmas sales for Apple. Earlier this week Piper Jaffray’s Gene Munster estimated that 2.3 million Macs may have shipped worldwide in the quarter, representing year-to-year growth of 43 percent.

Gartner’s and IDC’s results are preliminary and could change when the manufacturers release their sales figures. Apple is scheduled to announce it’s quarterly results next Tuesday.

Below the fold: Gartner and IDC charts of U.S. computer sales.