To be honest Bitt - and no matter how I say it here, it is going to sound as if I am being rude. You are wrong. There is a distinct difference between the realities of the engineering standards, and what (for example) the marketing departments of various different SCSI vendors decide is a cool name to sell the next performance iteration of a standard. You have unfortunately been taken by the marketing side ("Bitt - use the Force!") rather than the engineering side. Sorry Bitt, in this case I must try and take the high ground and say you're off base here. I can recommend "The Book of SCSI" by Gary Fields which explains the standards and also the progression of technologies, and the historical context of competition with the IDE based world. A lot of the material in the book is also available in the SCSI FAQ. Please don't just whack what I said without going to look it up: the SCSI standards have progressed logically from SCSI 1 to 2 to 3 (standards sets) and in each family standard, there have been improvements in physical transmission technologies, transmission path widths, state machines, device families, command sets, and many other physical and logical aspects. It is one of the best managed and logical engineering progressions I have had to deal with in some 20 years of electronics and software design, and to simply look at it from the point of view of "MarketSpeak" acronyms is pretty insulting to the people who have worked on it's development over the years.

As regards the transmission technology, well HVD was a mistake, since it required extremely expensive driver chipsets manufactured in small quantities by one maunfacturer with no second source (= expensive disks that people wouldn't want to buy). It didn't sell very well (for some reason, along with several other variations of the standards that you have proably not seen in the wild), especially since other manufacturers were offering far cheaper IDE technology drives. LVD was the saviour of SCSI and is the only reason it remained competitive - would you have been happy to cable your SCSI drives with a 6 cm gap between connector node points to guarantee performance? That's what HVD would have meant with standard cables, and you would have had to have paid twice as much per disk for the priviledge of being able to buy SCSI disks with performance to match what was available on an IDE drive at less than half the price?