Thank you very much for the clarification; Yes I was essentially trying to switch three drives off, but I'm reading your reply as saying both sides power all 6, and two sources are required to confidently support 6 drives plus the fan.
And what I have is different instances of the same OS as well as entirely different OS's running on different drives, as well as separate drives for common data sets, it all gets very confusing physically as well as for the OS's if they spot each other, also if I can switch the disk in the first slot it saves me messing around with boot loaders etc. I will just have to leave the drives ejected when not in use.
Your concept product MB524SP-B is perfect for my requirement, I like trayless a real time saver and the on/off switch is ideal (it looks cool too, it's on my wish list!) when will it be released?
The only thing I might want would be some sort of locking mechanism to prevent accidental ejection (not for physical security), but I only bring it up because my 6 year old knocked the power button the other day and sent it into the shutdown sequence, needless to say that function was quickly disabled, I guess I could just stop him playing in the office!
I suppose if I was after my ideal product (although I don't think it would be much use to anyone else) a way of selecting which SATA cable each drive was assigned to would mean I could swap drives around without removing them, although you'd probably need to hijack the standby voltage to be able to select drives whilst shut down, the more I think about it, the more complicated it gets...
Any way thanks again for your help,