Dell OptiPlex 390 SFF Case size?

The system description says it all, it is a Small Form Factor (SFF) case which is more of a Dell proprietary Dell case type . It doesn't really fit into any of the standard categories for case size/shape. I suspect that you want more of answer than this so ask away. But be aware they can be a real pain to upgrade. It is the smallest of these three, the biggest one is a mid-tower.
https://goo.gl/images/CxiLh8

Detailed sizes can be found on page 16 of this tech guide
https://www.dell.com/downloads/global/products/optix/en/optiplex-390-tech-guide.pdf
 

USAFRet

Titan
Moderator
It's just a case.
Not only will you have issues with the motherboard mount, you'll probably also have issues with e PSU mounting space.

$30 spent on a new case is far cheaper than the brain pain you'll encounter trying to make that Dell SFF case work with regular ATX parts.
 

spdragoo

Expert
Ambassador


^^^^^

This right here.

Better off getting a new case & a new Sandy Bridge motherboard...& even then, the listed CPUs for that particular model were so limited (i3-2100, i3-2120, i5-2400) that it might just be time to upgrade.