power supply upgrade
dell optiplex SFF
to upgrade the power supply you also need to replace the motherboard because they use a proprietary Dell connection.
but you cannot replace the power supply or motherboard without also replacing the tower they are located in.
this being a proprietary system means that standard components will not fit in it's available locations.
can I run a 1030 graphic card?
the GTX 1030s that i have seen do not require any PCIe power cable,
but the majority of them that i've seen require at least a 300w power supply.
you may be able to search around and find a model that requires lower power though.
if you are really looking to upgrade anything the best option will be to just start an entire new build.