Thanks lot for the explanations. As far as I understand there is some redundancy in the hypertransport channels: Only 8xx Opteron-models need every HTT-Channel to meet all specs. If one channel does not meet all spec, its gonna be a 2xx-Opteron, if two do not meet specs its an 1xx or an Athlon64. Parametric yield loss would only occur if all channels fail to meet specs - which hopefully is not a significant number.