Apple's delay in shipping the 27-inch iMac may have more to do with the sheer volume of sales than any problems with the graphics chips, according to numbers from market research firm NPD.
Stephen Baker, NPD's vice president of industry analysis, told CNET on Monday that for October and November, Mac desktop sales were up 74 percent over the same period last year. While NPD did not break the numbers down by desktop model, it's clear the iMac is a top seller.
In fact, the 27-inch iMac appears to be selling so well, it could account for the shipping delay that Apple apologized for on Sunday.
"It's not surprising Apple would be having problems supplying them [iMacs]," said Baker. "I can't imagine in their wildest dreams they would have thought they would sell like this."
Reports over the weekend suggested Apple was delaying shipments of the 27-inch iMac due to reported problems with the graphics card. While those issues remain, it may not be the root cause of the delay.
The surge in Mac sales was not limited to the 27-inch model. Baker said that the 21.5-inch iMac and the Mac mini are also doing very well.
Piper Jaffray financial analyst Gene Munster estimated in a research note to clients on Monday that Apple could sell 2.9 million to 3 million Macs for the current quarter, according to a report on AppleInsider. Munster cautioned that approximately 50 percent of all Mac sales for the quarter happen in December, so that number could change.
Mac notebooks saw a 5 percent increase for October and November, while iPod sales were down 11 percent year-over-year for the same time period.