CNET News.com learned of the action on Friday, which a Dell representative characterized as a "proactive replacement" and "not a recall."
The problem has to do with a flaw in how the Nvidia graphics chip works on the motherboards of OptiPlex GX200 computers. The glitch could cause images to be displayed improperly.
"In this case, we have a component that is not up to spec, so we are, therefore, going out and proactively contacting all of our customers to replace the boards," a Dell representative said.
But a Nvidia representative balked at the insinuation that there is a problem with graphics chip.
"This is not a chip-related problem," he said. Instead, "We are working with Dell to fix the motherboard design."
The Nvidia representative said that when Dell designed the boards, it chose resistor values that were too close to the edge of the specifications Nvidia supplied for its TNT2 chip.
"We're working with Nvidia to make sure we go out and replace all the potentially affected system boards," said a Dell representative.
A Dell representative said few, if any, customers would see a problem now, but "in the future there could be degradation of video performance."
"There's no chance of data corruption or any type of danger," another Dell representative said
Peter Glaskowsky, an analyst with MicroDesign Resources, agreed.
"Being it's a graphics system, all you're really likely to have is the chip not displaying the right information. That would sort of be the worst thing that could happen," he said. "Corruption of the operating system or data files is pretty much impossible."
Most GX200 models are sold to businesses. Models sold between May 8 and Oct. 12 of last year are affected by the problem. Dell would not say how many systems would need to be replaced, but a representative said, "This is not a significant portion of our mix."
After reviewing the system in relation to Dell's other commercial desktops, "There could be a lot of these things out there," concluded IDC analyst Roger Kay. "This is one of their mainstream, high-volume systems."
Because the graphics chip is embedded into the motherboard rather than residing on a separate card inserted into the system, Dell must go through the arduous task of replacing the motherboards. The Dell spokesperson emphasized there is no defect with the motherboard.
The Nvidia chipset is the TNT M64.
But Dell's graphics chip problem points to one of the inherent flaws with integrating components such as graphics, sound or network chips on the motherboard, say analysts.
Glaskowsky said that because the whole motherboard must be replaced, "the cost is much higher than a separate component. Most of the cost of these is dealing with customer dissatisfaction than the cost of the raw materials to replace them."
With a separate graphics card, the component could be more easily swapped out rather than with the more cumbersome and time-consuming task of motherboard replacement, Glaskowsky continued. "When you have a lot of things on the motherboard, it means there are a lot of things that can go wrong with the motherboard."
Still, Dell's direct business model gives it some advantages in dealing with this kind of situation.
"The good news story here is Dell can figure out where all these systems are, unlike a lot of other companies," Kay said. "They can identify right down to the beginning to the end of the run the systems affected."
Dell balked at characterizing the move as a recall. "A recall implies that there is something harmful or dangerous about the product," said a company representative.
"You can call it something else, but it's a recall," said Kay. "That's just semantics."
The OptiPlex situation is not Dell's first recall or part replacement. In October 2000 Dell recalled 27,000 notebook batteries. In March of last year, the company recalled defective memory chips installed on as many as 400,000 commercial notebooks.
Staff writer John Spooner contributed to this report.