The XPS 8950 3.5" HDD caddy is the same as the one in XPS 8940 etc.65KHD 3.5" HDD drive tray caddy (XPS 8910/8920/8930/8940/8950) right angle sata data cable comes in both orientations.  Dell cable is custom only in its length: it precuts cable to exact length for cable management.  you can certainly use a longer sata cable if you do not mind how it looks (in color and layout style). Given how the 3.5" HDD is installed in 8950, you would like a right angle cable with orientation like this.  assuming you plan to install the 2nd 3.5" HDD in the left upper corner of chassis, you need an extra long cable that is about 75 cm long (given the chassis is 37 cm x 43 cm) or 30".  Dell has a cable like that. Dell PowerEdge R900 MX550 0MX550 75cm Long SATA Cable [IMAGE] Need further assistance? Use the "Get Help Now" option at the bottom right to chat with a Dell technician right away.  [IMAGE]      
Hello all, I want to add a 2nd SATA HDD to my newly arrived XPS 8950.  I see a power connector, but no plastic disk carrier or signal cable. What part(s) to I order to facilitate the addition?  I can already see that some older disk carriers I had from an XPS 8930/8940 are not exactly compatible with the 8950 chassis and the right angle SATA data cables I have "point in the wrong direction" .. I am assuming that Dell uses a custom cable.
XPS 8950, add a 2nd SATA HDD