New GPU in Mac Pro 2008, some game graphics not loading properly

[emiliesaurus]

My boyfriend recently purchased an Nvidia GeForce GT740 2GB GPU for his Mac Pro 2008, he was assured by the shop assistant that it should work etc. He has put the GPU in the Mac etc. There is one problem we are seeing at the moment, on a few games they open up fine but certain graphics dont appear to be loading, I will try to attach an example if possible.
Any help would be greatly appreciated,
thanks!
http://i.imgur.com/1GNElWz.jpg
Emily.

 

[f-14]

take it to the mac store. apple are nazi/soviet dictators if an apple employee doesn't turn off nazi/soviet software restrictions apple by design will not allow end users to run/change anything not allowed/dictated by steve jobs himself.
p.s. apple software doesn't allow non apple approved software to run plus all the software incompatibilities built in by design of apple no nazi papers/soviet passport = straight to hell instantly.
touch screen support beyond iphone and ipod or ipad....not allowed with apple OS for mac...yet windows 7,8,10 have it. apple should be fixing this soon should require a new mac 2017 and or OS XL