By Aidan Malley

Published: 04:40 PM EST

After owners of the first-generation Mac Pro desktop voiced frustration that they couldn't upgrade to the GeForce 8800 GT video card, its creator NVIDIA is pledging an updated version that will work with both new and old Apple towers.

The graphics card maker's PR director has contacted Engadget with word that an updated version of the $349 add-on kit will contain firmware that supports all models of the Xeon-based workstation.

Currently, the card on sale through Apple's online store will only function with new-generation Mac Pro systems due to firmware that requires the new, faster PCI Express 2.0 interconnect standard, which was introduced for the first time to the Mac with the new towers. This has caused an uproar among owners of the initial computer, which has been limited to the now two-year-old ATI Radeon X1900 XT as their fastest mainstream graphics choice.

"I am afraid they don't care and prefer forcing people to buy a new high-end machine just to have a graphics card update," says one user from Apple's discussion forums.

The restriction has also been unusual in the graphics upgrade market, as many video cards for Windows PCs that support the version 2.0 standard also include backwards compatibility for the outgoing format.

The new Mac Pro's default video card, the ATI Radeon HD 2600 XT, is not available as an upgrade kit but has been successfully tested with older Mac Pro units, according to multiple reports.

NVIDIA's press director has not said precisely when the company's replacement video card will be available, only noting that the new GeForce 8800 GT for Macs will be available "in a few weeks" from Apple's website.