Just saw your iMac upgrade for GTX 780m.

My imac 2011 27" graphic card HD 6970m seems to have problem now. It shows Pink lines when booting up and stuck. I was told that I'll be charge RM 2,9xx for fixing it. Until I start doing some research and found your thread.

I also found cheap GTX 780m and also HD 6970m Graphic cards in Taobao. Do you mind if I ask you any question during my quest of fixing my own iMac?

Thanks.