On Mon, Jun 22, 2009 at 2:55 PM, Clark Martin<[email protected]> wrote: > The standard 3.5" & 5.25" drive power connector supplies +12V and +5V. > 2.5" drives only need 5V so they would just use that power line. There > is no 3.3V line on drive power cables.
I'm not sure exactly what you mean. Yes, I think all the external power supplies I've seen have only supplied at most +12v and +5v. But the SATA spec apparently specifies that pins 1 to 3 of a standard 15 pin SATA power connector should supply 3.3 volts. I doubt any of the current 3.5" drives actually depend on this, but it's apparently part of the spec. I don't know about 2.5" drives, but I suspect they only need 5 volts as you said. I've seen speculation that some of the solid state memory drives might require the 3.3v supply, but it was just speculation. I really have no idea why the SATA power connector is supposed to provide 3.3 volts to some pins. But apparently that's what the spec says. (I thought about ... and immediately rejected ... poking around with a volt meter in my SATA external enclosure's power connector to see what it supplies to pins 1 to 3. Knowing me, I would be sure to short some pins to ground and destroy a perfectly good enclosure. A geek's gotta know his limitations ...) -irrational john --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
