Why Lenovo’s PCs are outselling Apple’s Macs

There are a few caveats worth mentioning (see below), but there’s no getting around the fact that Lenovo — a Chinese company founded in Beijing in 1984 —  is on a tear.

• It bought IBM’s personal computer business in 2005 and by 2013 had become the world’s largest PC vendor by unit sales.
• It entered the smartphone business in 2012 and is already the largest vendor of smartphones in mainland China.
• It has agreed to take off Google’s (GOOG) hands a storied U.S. brand — Motorola Mobility — picking up for $2.91 billion the better part of a company for which Google paid $12.5 billion just two years ago.

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This is a deeply ironic turn of events. IBM (IBM) got out of the PC business because the margins on Windows boxes were too thin. Lenovo took over IBM’s ThinkPad brand — thin margins and all — and is chewing up the U.S. PC market

I wouldn’t want to be selling Android boxes when Lenovo enters the U.S. smartphone market with the Motorola brand.

Those caveats:

• Neither IDC nor Gartner counts iPads or tablets as PCs, although Gartner counts what it calls mobile PCs (but not Chromebooks) while IDC counts both netbooks and Chromebooks. Tablet sales may have slowed, but if they were counted, Apple would be in the No. 1 PC maker in the U.S., not No. 4.
• PC sales in the U.S. got a bump last quarter because Microsoft in April discontinued support for Windows XP, prompting IT managers to replace millions of aging Windows boxes. The Mac got no such bump.
• Gartner’s and IDC’s public estimates are “preliminary” and not verifiable. Apple releases quarterly Mac unit sales, but doesn’t break them down by country. In Q2 2013, it sold 3.75 million Macs worldwide. According to Gartner and IDC, 1.7 million of those Macs were shipped to the U.S.

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Below: IDC and Gartner’s U.S. spreadsheets for Q2 2014.

IDC:

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Gartner:

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Follow Philip Elmer-DeWitt on Twitter at @philiped. Read his Apple (AAPL) coverage at fortune.com/ped or subscribe (free!) via his RSS feed.