Corsair VS450 in a Dell Optiplex 790 mini tower?

Solution
can it fit in the case, likely

to answer your question you have to answer 2

1. the power connector on your motherboard is it a 20 or 24 pin or something else?
2. the main board 12v connector is it a 4pin or 8pin or something else?

Dell tends to not do things like the rest of the industry standards to keep you stuck with their hardware.



It has the 24 pin, and the 4 pin CPU connectors. Should be OK.
I would look at the 5V. rating on the old PSU and be sure the new one has enough current there. Dell used that rail more than aftermarket/ newer systems and sometimes PSU swaps fail due to that. You might even need to go to a 500W or bigger PSU to get what you need there.