Why GPU?
•Much less CPU utilization
•Very little AGP/PCIe bus utilization
•Small system memory requirement
•Small video memory requirement
•Significant rendering speedup
The version of Geometry clipmaps that appeared at Siggraph this year had most of its components implemented on the CPU.

The current system has most of its components on the GPU. So why do we want to do this on the GPU?

Firstly, this leads to very little CPU utilization. The CPU is used only for decompression, which I’ll be talking about later. If the data is synthesized the CPU’s role is very minimal.

Secondly, there is very little bus utilization. The bus needs to be used only for upload of decompressed terrain residuals.

We used shared vertex and index buffers in all levels resulting in a very little video memory requirement. I’ll be talking more about this later duirng the talk.

Finally , we hope to attain much better frame-rates than a similar implementation on the CPU.

Please note that using the GPU is possible only because each of the clipmap levels is a fully regular grid.

Our implementation uses DirectX 9 and Shader model 3 supported by the nvidia geforce 6800 card.