According to 9to5 Mac, supplies for all four of Apple’s current iMac models are low in multiple countries — including in the United States and in an unnamed Asian country. The low supply counts suggest that Apple is poised to announce a refresh of its iMac line of computers in the very near future — which it last did on July 27, 2010 when it updated the family with Intel’s new Core i3, Core i5, and Core i7 processors. Apple’s suppliers are reportedly low on hard drives and graphics processors, specifically, although Apple is not the only computer manufacturer to sell devices equipped with ATI Radeon HD 4670 or Radeon HD 5670 graphics cards. Apple may introduce a new family of iMacs later this month or in early May. Rumor has it that the new family of all-in-one desktops will pack Intel’s Sandy Bridge processors and the new Thunderbolt I/O port, which made its debut during the Macbook Pro refresh.