AMD GCN Performance Tweets and Depth Bounds Test DX11 Demo Published

1 – GCN Performance Tweets (May 2013)

Here is a document that lists and details GCN Performance tweets posted by @NThibieroz:

This document lists all GCN (“Graphics Core Next”) performance tweets that were released on Twitter during the first few months of 2013. Each performance tweet in this document is accompanied by additional details to complete the information provided on Twitter.

You can download GCN Performance Tweets HERE

2 – Depth Bounds Test Direct3D 11 Code Sample

DepthBoundsTest11 shows how to use the AMD Depth Bounds Test extension, a feature of the AMD GCN architecture, to limit rendering within a specified depth bounds. By limiting what pixels are rendered, some graphics techniques can run faster because fewer pixels need to be rendered, and therefore fewer instructions executed by pixel shaders.

Depth Bounds Test is a hardware feature that causes the GPU to cull pixels if the depth buffer value is outside the specified range. This is different than the way we normally think of the depth buffer working, where the depth value of the pixel is compared to the corresponding value in the depth buffer. The sample uses this behavior to optimize deferred shading. By setting the depth range to the depth range of the light, the sample
is able to cull pixels that are either too near or too far to be affected by the light.

You can download the Depth Bounds Test DX11 Code Sample HERE

In OpenGL, the depth bounds test can be done using glDepthBoundsEXT() (see GL_EXT_depth_bounds_test extension). On AMD Radeon cards, depth bounds test is only supported by Radeon HD 7000 and higher+ cards.