Perforated Copper Sheet or Plain Flat non perforated?

[chris189]

As you all know, EVGA stopped producing the backplates for the GTX 470 specifically. I would use the EK backplate but it's meant to be used in conjuction with the EK Water block. So I have decided I'm going to be custom engineering my own pure cooper backplates for my GTX 470's in SLI. I will be having them precision laser cut to specification and I will be cover the entire back side of the pcb with thermal pad material. There will be the intake hole cut out of the copper however. Anyway so i'm in the process of deciding what type of copper sheet I will need. Would you guy's say a perforated copper sheet would yield enough of a temp difference over plain flat sheet? I'm not sure if I want to invest the additional time and money for .5C lol. Also there are different types of copper. Normal typical copper and the C101 Oxygen free copper. To my knowledge oxygen in a mating surfaces worst nightmare and i know heat doesn't transfer as effectively when oxygen is present in the metal material. So ideally I would say C101 would be preferred and it's not outrageously expensive either. Your thoughts?

THANKS!

 

[rubix_1011]

As long as it's a backplate and there will not be contact with water, I'd say aluminum with some milled fins would work just fine. Probably cheaper.