Question: what is the difference between dell optiplex 7010 and 9020?
Answer: As far as I can tell, you're talking about the Optiplex computers? The 7010 appears to use a third gen core i5, and the 9020 uses a fourth gen i7. So you would need to buy a new (old) motherboard to use the i7… But Intel is currently on 9th gen core chips.