http://www.hdmi.org/learningcenter/kb.aspx#49 FAQ: What is the difference between a “Standard” HDMI cable and a “High Speed” HDMI cable?
Recently, HDMI Licensing Administrator, Inc. announced that cables would be tested as Standard or High-Speed cables.
•Standard (or “category 1”) HDMI cables have been tested to perform at speeds of 75Mhz or up to 2.25Gbps, which is the equivalent of a 720p/1080i signal.
•High Speed (or “category 2”) HDMI cables have been tested to perform at speeds of 340Mhz or up to 10.2Gbps, which is the highest bandwidth currently available over an HDMI cable and can successfully handle 1080p signals including those at increased color depths and/or increased refresh rates from the Source. High-Speed cables are also able to accommodate higher resolution displays, such as WQXGA cinema monitors (resolution of 2560 x 1600).