But the two chips are 99.99% sure not to be the same. The date code is your clue here and more.

Always supply what board this is and see if Dell has service docs on this model. I couldn't supply this because I'm not sure of what you have here and which board. So now you know Dell has a lot of service docs so go see what they have. Also, see what's in the market for the board or machine since repair might not be possible as Dell never published the schematic.