DailyTech - Both AMD and NVIDIA have received subpoenas from the U.S. Department of Justice Antitrust Division in connection with the DOJ’s investigation into potential antitrust violations related to graphics processors and cards. The root of the AMD subpoena is its recent acquisition of ATI Technologies last month, which was approved according to Canadian antitrust laws. The DOJ has not made any specific allegations against AMD, ATI, or NVIDIA. Both AMD and NVIDIA said that they intend to cooperate with the DOJ in its investigations. Together, AMD and NVIDIA hold just over half of the entire graphics market, each with about an equal share. Following the news, NVIDIA shares fell 3.6 percent on Nasdaq trade, while AMD shares fell 2.1 percent on the New York Stock Exchange.