[IMAGE] It has 4 sata ports (one blue two black one white).  If you have an optional ODD, then there are three left for HDD/SSD.  If no ODD, then 4 HDD/SSD max. note the white sata port is reserved for optional odd, but there is nothing stopping you from giving up odd and using the port for hdd/ssd.  as far as mobo is concerned, it does not matter whether it is odd or ssd. its 2.5 bay can accomodate two 2.5 hdd/ssd [IMAGE] Its 3.5 bay can accommodate one 3.5 hdd, but you can install two 2.5 ssd/hdd there using a 3.5 to 2.5 adapter.  [IMAGE] [IMAGE]  
Looking at getting an 8940 and getting mixed results from existing posts here.  Some say it has 4 SATA ports while the manual and other posts say 3. As shipped, assuming I supply the cables, can the 8940 support 4 HDD's?  2  2.5" and 2 3.5" Confused as to why they would have the physical bays for 4 drives knowing that the system can only support 3? 
XPS 8940, 4 bays but only 3 SATA ports?