What we are seeing is a new standard for really high speed data where certain steps in the hand shake may be problematic. 1.66gps is an asoundingly fast data rate. How many gigbit computer networks have you seen? I recall having to set some computers to half duplex 10baseT to get them to communicate with some of the first cable modems. What I am told we are seeing is manufacturers implementing the EDID and HDCP handshakes in the least expensive way possible. This handshake takes place but once and if anything is missed there is no way for one device to tell the other to send it again. This all strikes me as similiar to how serial protocols are generally used by those of us in the CI field. We use them as one way protocols because using feedback is too costly and possibly too difficult. It works as long as the wire is not very long and the data rate fairly slow.

Yet the HDMI standard is still changing and the data rate is really fast. It does appear to varry from manufacturer to manufacturer as some take the higher road. The cable does seem to be imporant, especially the termination. At these data rates having every wire the same length and terminated at the exact same circumstances supposedly matters. How did I learn about any of this? I took Michael Tinsberg's class at CEDIA on digital video standards. I would not say the class was empty but there were plenty of seats in the class I was in. Final quiz: According to the specification, what is the longest a HDMI wire is supposed to be? I think you will find that many of the problems begin at this little fact. Everyone assumes short cable runs between decentralized equipment. We generally centralize equipment and so are pushing the standard beyond its capabilities. This happens in serial communication too. I can send RS232 data or composite video much father then the specification permits. But those standards have been around for a very long time. As installers we have less experience and few product solutions to our issues, partially as these issues have still being discovered. I have a fairly high end lab in my office. I have no devices with HDMI in them. I have still to see the new Integra equipment with HDMI switching that we saw at CEDIA. There will be a shake out period.

Alan