I ended up getting a discount on a Late 2011 iMac, and I took it apart to upgrade it. Besides the information listed on EveryMac, some things I discovered are:
- You cannot add a Mid 2011 iMac Bluetooth module to a Late 2011 iMac – the motherboard of the Late iMac just doesn’t have the logic to support it
- You can upgrade the WiFi chip in the Late 2011 iMac to the one used in the Mid 2011 iMac – I didn’t do this, but it should be possible. You would need a Mid 2011 iMac Apple Airport card, as well as an extra antenna (specifically the one screwed into the bottom left of the bezels)
- You can NOT use Target Display Mode (TDM) on the Late 2011 iMac. One of the main differences between the Mid iMac and Late iMac is that the Mid iMac uses a Thunderbolt 2 port, while the Late iMac replaced that port with a Displayport port. Both are the same dimension, but the Late 2011 iMac can not be used as a display – it can only output display.
- You can upgrade the CPU in the Late 2011 iMac, even to a Xeon – I think there was a video published by “Macintosh Men” on YouTube a while back that said you couldn’t upgrade the CPU in these 2011 iMacs to anything “non-standard” (aka any CPU apple didn’t include in their lineup, aka a non-Core i3-2100s or Core i5 2400s or Core i7 2600s). I upgraded the CPU in my Late 2011 iMac to a Xeon E3-1270 and it was awesome. There’s no CPU graphics acceleration, and I couldn’t get Airdrop to work on Catalina after using Dosdude’s patcher, but for me it didn’t matter.