216-081000 to 215-0798006 iMac 2011

[Mrmani]

hey all
I replaced the bag 216-081000 to 215-0798006 1gb Vram the machine works fine except when I do heavy graphics on YouTube the screen blanks off and I feel the machine gets hot.I have installed High Serbia 10.13.6 ,I also shifted the odd sensor to the gpu heatsink that helped a little but then again the same thing.
So question do I need to check the Vbios and also the Efi as I read in some post they have to match.
thanks

 

[16v]

Maybe High Serbia is the Problem!
Looool

 

[Mrmani]

oooppppsssssssssss high Serria auto correct hehehehehehe nice one 16V for a min I was trying to figure out where did high Serbia come from .My mistake ???
cheers Mate