QCT tower = Optiplex 7030 tower

QCS SFF = Optiplex 7030 SFF

QCM Micro = Optiplex 7030 MFF

All Q desktop are new Dell business class PC

Q chipset

ECT tower = Inspiron 3040 tower 

ECT and QCT use same metal chassis w different bezel and motherboard.

ECS Slim desktop= Inspiron 3040 small desktop

ECS and QCS use same metal chassis.

(Inspiron is Economy line for general consumer)

Z chipset

ACT tower = Aurora R17

AAT tower = Area 51 R8 (internally called R8)

A for Alienware gaming PC line