Supply of Apple's existing Mac mini lineup has become increasingly constrained over the past two weeks as the company prepares to introduce refreshed models that may serve as a harbinger for some new I/O technology on the Mac.

The shortage has been verified four times over by AppleInsider, which has received numerous reports that suggest the constraints are indicative of new models on the horizon, rather than intermittent delays resulting from the onset of the back-to-school buying season, which sometimes sees Apple curb the flow of Macs to its distribution channels in favor of filling large orders to universities.

For example, one buyer for a higher-ed institution placed a bulk order for Mac minis two weeks ago through the school's Apple rep, noting that receipt of the machines was required by June 1. Although the Apple representative initially indicated that the delivery date would not be a problem, the buyer last week saw his ETA pushed out from 1-3 business days to a definitive date of June 14.

"Every time this has happened in years past, it means that the item we ordered would be revised," the buyer told AppleInsider.

Meanwhile, another Mac consultant serving as a buyer for a separate firm ran into similar problems while attempting to secure some high-end Mac minis. This person was informed by his supplier that the model was completely out of stock at the distributor, which had no ETA from Apple on when restocking would occur.

Similarly, a third person who regularly purchases Mac minis in bulk directly through the Mac maker was advised by his Apple contacts to only submit his latest order for what he absolutely needed "for the next few weeks," serving as yet another hint that the days are numbered for existing models.

Those reports of Mac mini shortages were further corroborated by AppleInsider's own routine checks while updating its Mac Pricing Guide. As of this week, roughly half of the resellers who maintain a seat in the pricing guide began reflecting no inventory of either current Mac mini configuration and are recommending that customers call in to check on availability. Calls to these resellers suggest new orders won't be filled until next week at the earliest.

All of these findings bear all the telltale signs that Apple is ramping down production of existing Mac minis and preparing its distribution for refreshed models. In March, AppleInsider exclusively reported that next-generation Mac minis making their way through the Cupertino-based company's verification tests were seen with an HDMI port in place of the existing model's DVI port.



Apple's existing Mac mini offers users the choice of DVI or mini DisplayPort for video output.

At least one of the Mac mini prototypes described by those privy to the hardware was said to include Nvidia's MCP89 chipset, which is the successor to the existing MCP79 (or GeForce 9400M) chipset found alongside Intel's Core 2 Duo processors across the majority of Apple's 2009 Mac product line. Both tips came by way of the same people who accurately predicted in February that Apple was about to introduce advanced automatic graphics switching on its professional MacBook Pro line — a prediction which panned out when the company unveiled new models in April.



An unannounced version of the Mac mini has been spotted with an HDMI connector instead of a DVI.