5K iMac CPU Upgrade

First, I must warn you the newer 'Thin Series' iMacs are a bear to open. Many people have damaged the display assembly just trying to open the system. Make sure you use the correct tools and follow the IFIXIT guides as its very easy damage the display.

OK, Heres the specs for your systems CPU and the top version Apple offers:

• Intel i5-4690 3.5 GHz Processor
• Intel i5-4690 4.0 GHz Processor

Both of these chips use a FCLGA1150 connection to the logic board. FC stands for Flip Chip and LGA stands for Large Grid Array, the number 1150 is the number of pads the chip has. Here's an image of the iMac's logic board: Logic board with heat sink removed. Note the clear plastic corners this is the alignment frame. The chip is soldered to the logic board.

I don't know of anyone has even tried to desolder this CPU. It would be a very expensive experiment ;-}

Frankly, if you really need more CPU power I would recommend selling your iMac and instead buying a Mac Pro. It offers 8 & 12 cores unlike the iMac with only 4 and it offers a much deeper L3 cache (30 MB). It's also a lot more expandable internally and externally.

FYI - Intel doesn't offer these chips individually, you must buy a cane of 25 chips.