Chosen Solution

So I am a Filmmaker and my current iMac runs an i5 Processor with the Nvidia GeForce GTX 660M. I need a more powerful graphics card (preferably the 680 MX). I’m looking at a few logic boards and I hope to replace it with a logic board from the same year and with the i7 processor and the 680MX Graphics card. I was wondering if this is at all plausible because it would help bring some new life to my computer and work flow.

According to Changing Logic Board to allow i5 to i7 upgrade it’s entirely possible to replace a logic board of an older model. Although a replacement logic board for this model is ~500 dollars, you could start with upgrading the RAM and HDD/SSD first to give it a bit more power, but TBH if your willing to drop the cash for the logic board upgrade you might consider a whole system upgrade.