this is a simple rack for team blue cpus 14 slots in total.

x1 ,x2 ,x3 support only land grid array (LGA) cpus.

x1 is compatible form core 2 duo till the newest core ultra 3, 5, 7 or 9 so this includes almost all core i3 ,i5 ,i7 ,i9 ,pentium ,celeron ,core 2 duo ,core 2 quad and some xeon E3 cpus with the same socket.

so that means it is tested and supported with LGA 775, 1366 ,1156 ,1155 ,1150 ,1151 ,1200 ,1700 ,1851.

x2 is compatible with i7 960 ,i7 970 ,i7 990x and xeon 3500 ,3600 ,5500 ,5600 series cpus with socket LGA 1366.
 

x3 is copatible with xeon E5 1600 ,2600 ,4600 V1 V2 V3 V4 and core i7 3800 ,3900 ,4800 ,4900 ,5800 ,5900 ,6800 ,6900 with LGA 2011(-3) cpus.

the v2 means that length is 100mm.

xeon E7 ,team red and pga cpus are not yet supported, but i will add them when i get some to test. 
pentium 4 has the first priority.