What Voltage Runs the Harddrive?

[JBunn]

Which voltage 12v or 5v runs the harddrive or does both of them? If you cut the power to the 12 volt wire will that keep the bios from picking it up on boot up? Or is it the 5 volt or both? What I am wanting to do is put a switch on one of my hardrives to keep it turned off because I don't use it that much and I am kind of thinking it would last longer if it wasn't running all the time I have my Puter on if I don't need it,
Any comments would be appreciated.

Thanks

[NDC]

That would be very simple to make... That's what I do on my EIDE Internal CDRW drive. Just putting the switch on the red wire will prevent the BIOS from detecting the drive when power switch is turned off. I put a switch on it since I only use it when needed. I don't burn CD's that often...

This is an image that was made for my BB a while back. Here is a simple diagram of how to make it...


<IMG SRC="http://ndcmj.hihome.com/cdrwpwr.gif" border=0>


Another suggestion for you would be to add a mobile rack to your external 5.25" bay so that you can just slide the rack out when the HDD is not needed and pop it back in when you do need it. That's what I do with my HDD's http://www.sysopt.com/forum/smile.gif


Hard Disk Rack (http://www.aiyamicro.com/mobile_racks.htm)




[This message has been edited by NDC (edited 06-25-2001).]

[JBunn]

Thanks NDC. Thats pretty neat. That's exactly what I am going to do....

[Szech]

JBunn, the hard drive uses both wires, but without the 12v, it won't be detected as NDC pointed out. I've thought about doing this, and IMO, I would rather cut the ground wires, to make sure that no current (+12v or +5v) would be going through it, and make a switch to close the ground circuit when I wanted it on. The black wires all come together in the power supply anyway.

[JBunn]

Thanks Szech, that should work also. I plan on mounting a switch for my extra harddrive and my cd-rw. I don't use them a great deal, so why should they be running. They may last longer that way, then again they may rust up. Is there anyway for the system to reconize the IDE devices after it has booted up or do you have to re-boot each time you want to use it if you have it turned off? I know that you can go and refesh a SCII device but don't know of anyway to do a IDE...

Thanks

[NDC]

If you have the switch off when the BIOS is going through a detection and you boot into Windows, simply turning on the switch and rescanning for device in Device Manager will not give access to the drive... EIDE devices must be detected at system boot up by the BIOS for it to be accessible in Windows.

As for SCSI devices, it won't matter if you boot up with the switch off and turn the switch on and scan for the device in Device Manager. It will be detected and you can easily mount and dismount the drives by turning on and off the switch and doing a scan for new hardware in Device Manager... This method works on all MS OS's including Win2K and NT4, as for ME, I haven't tried it personally but I think it should work with no problems...


What I've been thinking of doing is get a HOT-SWAP USB external mobile rack case that will allow you to mount and dismount any EIDE device simply by plugging in the rack and pulling it out. A buddy of mine has one and it mounts fast! It takes about 6 seconds for the IDE hard disk to be detected in Windows.

[This message has been edited by NDC (edited 06-27-2001).]