Hi T420 supports Internal controllers: PERC S110 (SW RAID) PERC H310 PERC H710 PERC H710 only, I'm afraid. 
Hi all, I have an older T420 that's new to me. I'm about to populate it with drives from scratch. I don't really have any plans to use the PERC directly, since the box will be running unRAID, but my (very limited) understanding is that the RAID controller has to at least recognize the drives, yes? Anyway, I've found an excellent deal on some brand new 4TB drives, but they're 4Kn formatted. It seems like my reading is indicating that the machine won't recognize these drives as they are. Do I need to replace the PERC H310 with something else? If so, what? Would reformatting/flashing the drives be an option? I'm not sure of the best option, or if buying these drives is just a bad idea all around.
T420 - 4Kn drives?