[NAME]  The Dell R494D R494D on Ebay R494D on Amazon  fits inside 65KHD  3.5" HDD caddy Precision 3630/3640PowerEdge T40/C6525XPS 8910/8920/8930Aurora R5/R6/R7/R8/R9/R10/R11 and holds 2X drives whereas the 3.5 bay holds only 1 drive.  You can find this part on amazon and ebay etc.  You will also need the sata power splitter N701D  N701D SATA POWER SPLITTER and 2 sata data cables.  DC094 and M8865 SATA DATA CABLES Another NON DELL alternative is SILVERSTONE SDP08 SilverStone SDP08 on Amazon  which has the mount points of a standard 3.5" hard drive, and . It holds two 2.5" devices stacked. Its not compatible with all dell models however because its larger than R494D. [IMAGE] [IMAGE]     [IMAGE]   [IMAGE]        
Just got a "guarandied compatible"  2.5" caddy adapter for my new precision 3640 tower from E*ay. Of course it was by no means compatible. IMO it should be easier to get such a basic stuff. Or, to be precise(ion), Dell should ship with one of those. Some could argue that "nobody needs a second hdd", but, hey, this is a workstation, and there is still a 32bit pci slot and very old fashion ps/2 mouse/keyboard ports on 2020/21er Dell workstations... Dell, please provide a part number and inform interested people where to order the part. Thanks
2.5 to 3.5 hard drive caddy