It "looks" like you could get away with a 1700x or 1800x, without having to change the motherboard.
The problem is, that DELL may not use standard motherboard... sizes, so you may need a case too.
/e This would work...
https://pcpartpicker.com/list/w9GLq4Or this...
https://pcpartpicker.com/list/kWjTZR/ee There are a few cheaper motherboards, but they might require a BIOS update.
Found a slightly cheaper case...
https://pcpartpicker.com/list/4wbVvnWell, there are tons of cheaper cases, but this is a cheaper, good case.

/eee What is the exact Dell computer you have? Dell 5675?
This post was edited by Ghot on Mar 16 2019 07:03pm