AMD served Skype with a subpoena on Tuesday demanding documents related to its deal to make a new 10-way call feature in Skype's latest version available exclusively to Intel users.

AMD believes Intel has provided Skype with financial incentives to limit the 10-way conference call feature of Skype 2.0 to Intel dual-core processors. Users with AMD dual-core chips or single-core chips are restricted to hosting five-person conference calls because only Intel's chips offer the performance necessary to host the 10-way call, according to Skype.

"There is simply no technological reason for the decision to limit the 10 way calling feature to Intel dual core processors and the temporary nature of that restriction only makes our point stronger," said AMD Global Communications consultant Michael Silverman to a CDRinfo journalist.

Indeed, the 10-way calling feature will be exclusive to Intel's chips for a limited time, according to Henry Gomez, Skype's North American GM. "Skype is not releasing the time frame for the expiration of the exclusive agreement", he said when the latest version was released.

"If AMD processors are permitted to access the 10 way calling feature six months from now (or whenever they decide to end the restriction) there should be no reason why AMD processors shouldn't be able to run 10 way caling today," adds Michael Silverman. "Hundreds of credible 3rd party reviews worldwide have proven that AMD is the clear performance leader over Intel. We feel confident that our processors - if allowed to compete fairly - would deliver equal and likely better performance for Skype customers who use the 10-way conference calling service."

This latest legal filing adds to a long list of subpoenas AMD has filed in an attempt to prove that Intel has used its dominance of the x86 PC and server processors market to prevent AMD from winning business with certain partners. Intel has denied those accusations, and the companies are preparing for an antitrust trial that promises to reveal a lot of details on the inside PC industry.

An Intel representative confirmed that there are no instructions that specifically enhance the performance of voice over Internet Protocol (VoIP) software like Skype's in Intel's dual-core chips.

An Intel representative did not comment when contacted by the CDRinfo team.

To read AMD's point of view on Intel's inequitable business go to AMD.