AMD's chipsets for Zen-based processors, which AMD outsourced to Taiwan-based ASMedia Technology for R&D, are rumored to be seeing design issues, which will increase motherboard players' costs. AMD's Zen processors are seeing stable development and have a satisfactory yield rate, and about to enter the engineering sample stage in the near future. However, according to Digitimes.com, motherboard players are seeing the chipsets designed by ASMedia having some issues over USB 3.1,

According to the report, Zen chipsets' design limitats the USB 3.1 transmission speeds as circuit distance increases, forcing PC and motherboard players to add additional retimer and redriver chips or even an independent USB 3.1 IC in order rectify things. This has thus increased the makers' costs by US$2-5, according to sources from the motherboard industry.

Since PC sales have been weakening and the increased costs are likely to impact motherboard players' demand for the Zen chipsets, AMD is reportedly considering acquiring retimer and redriver chips via third-party suppliers to sell along with the Zen chipsets, but so far the sources have not yet heard any firm details on costs or development.

AMD said it is pleased that Zen is on track and will not comment on customer specific board-level solutions, while ASMedia clarified that this is purely a market rumor and its product's signal, stability and compatibility have all passed certification.

AMD Zen chipset designs will begin shipments at the end of the third quarter and start mass production in the fourth.