"...CD recorder manufacturers seeking to achieve ultra high writing speeds have been constantly developing new techniques, enhancing older ones and applying any sort of tweaking to their drives. Sanyo was the first company that announced a Zone-Constant Linear Velocity (Z-CLV) recorder. The only other manufacturer who has developed a rivaling technology is Yamaha, which Partial Constant Angular Velocity (P-CAV). CD recording fans are expected to ask: What are them? How can they be compared against each other? Which technology is faster/better? So, let's find out..."
FULL STORY @ CDRINFO (http://www.cdrinfo.com/articles/pcav-zclv/index.shtml)