Overdraw?

[Steg]

Ive seen overdraw mentioned on several sites when it comes to benchmarking graphics cards and i still am not sure what it is. Is it just where the card is rendering multiple polygon/texture layers on top of each other - thus blocking out the one behind it? Or is it something all together more complicated?

Steg

 

[Didou]

Overdraw is when the GPU renders polygons that you never get to see. The PowerVR architecture is based on that alone, smart rendering. Figure out how the final frame will look like & render only the visible parts.

Hyper-Z has adressed that on the ATI, but I don't think the LMA for nVidia does.

Here's a very good article, if you're in the mood for very technical explanations -> Tile Based Rendering Explained at Beyon3D

 

[Rick]

This is the same thing as HSR, right? Hidden surface removal?

 

[Didou]

TBR ( Tile Based Rendering ) is only PowerVR's implementation of HSR ( Hidden Surface Removal ).

Not so long ago, right before its demise 3dfx had come out with a software version of HSR -> 3dfx HSR Tweak Guide @ TechSpot.

They had also acquired GigaPixel which had a technology similar to TBR & were going to implement it after Ramapage. nVidia owns that technology now but I doubt they've used it in anything up to now.

 

[Steg]

interesting....cheers people

Steg