Early 2011 MacBook Pro OS

Hello! My kid’s Mac hard drive died so I put in a new SSD. Yay speed! It automatically installed, uh, Maverick? The one with the M. It’s an early 2011 MacBook Pro, core i5, 4GB memory.

Which is really the most recent OS that I should upgrade to on that? Sierra is hypothetically compatible, but will it be super slow?

(Maybe this should have gone into IMHO?)

I have Sierra on a Core i7 Macbook, 2011 vintage, and it runs fine.

I have a 2013 Air, core i5 and 4Gb, so similar to your Pro. Sierra works great.

I am running El Capitan on 2009 Mac Mini with no problems (also Win7 via Bootcamp). I think Sierra would be fine.

Thanks, everyone! I went with Sierra and, with the SSD, it seems faster than ever. It was surprisingly easy – the Mac must store the wi-fi information in non-volatile memory of some sort. When I connected the new, totally blank, drive, it was still able to connect to the network.

It’s all up and running. Thanks again!