this card would fit 990 MT.  148 x 106 x 42 mm (5.8" long) double slot width.  this is a 23W card supported by the PCIex16 slot. [IMAGE]990MT
Hey, could I even fit this in my computer? here is the link to the exact one. [URL]
Dell Optiplex 990 can I fit a msi geforce gt 730 4gb card