Third HD


Intell

macrumors P6
Jan 24, 2010
18,872
368
Inside
MDD's have three IDE buses in them and room for 4 HDDs and two optical drives. You can simply put the other drive in the bracket under the optical drives or in the rear bracket and connect it. You may have to set the jumpers to be cable select on the third drive.
 

paulwgraber

macrumors regular
Original poster
Dec 13, 2013
109
1
I don't have a second optical drive so I can just put it under the first one?
 

archtopshop

macrumors regular
Dec 13, 2011
206
1
I don't have a second optical drive so I can just put it under the first one?
MDD's have two drive cages for 3.5" hard drives. Each can hold two drives for a total of four, not counting the two optical drive bays.

The drive bay under the power supply use the ATA-100 connector next to the cpu heatsink. The drive bay under the optical drives use the ATA-66 connector nearest the optical drive bay fan. The optical drives use the ATA-33 connection nearest the door hinge.

The drives bays are identical and interchangeable. If you are missing the one under the optical drive cage, you can find them for sale on ebay for not too much money.
 
Last edited:

robertdsc

macrumors regular
Jan 28, 2014
202
5
MDD's have two drive cages for 3.5" hard drives. Each can hold two drives for a total of four, not counting the two optical drive bays.

The drive bay under the power supply use the ATA-100 connector next to the cpu heatsink. The drive bay under the optical drives use the ATA-66 connector nearest the optical drive bay fan. The optical drives use the ATA-33 connection nearest the door hinge.

The drives bays are identical and interchangeable. If you are missing the one under the optical drive cage, you can find them for sale on ebay for not too much money.
Fitting a 3.5 inch hard drive into a 5.25 inch drive bay will require an adapter. I've tried several versions without success. The layout of the IDE connections for a hard drive is different than an optical drive and the connectors don't line up properly.

OP, what you could do is do a Google search for "MDD Drive Cage" You can find them on eBay and other places. Once you buy one, you can insert two drives into it, then attach it to your MDD.

See this picture:



The six drives you see are contained within the MDD drive cages. The cages slide into slots on the MDD's case set aside for that purpose.

The two on top of the "shelf" where the optical drive should be use the ATA/33 connection without issue. I removed the optical drive and cage to make room.

Before you do all that, though, take time to learn how to use IDE jumpers and jumper settings. If your drives are not set properly, they won't appear on your Mac, no matter what you do. It took the better part of three hours one night to figure that out for me. Once I found that out, the second Mac I worked on took ten minutes to assemble.