For performance issues, you might want to check out the AMD ShaderAnalyzer. Its free software, and helps you see the bottleneck of your shader, as well as approximate performance with ATI/AMD cards. I don't know if it supports Nvidia cards tough.

link: http://developer.amd.com/tools/graphics-development/gpu-shaderanalyzer/

For performance issues, you might want to check out the AMD GPU ShaderAnalyzer. It's free software, and helps you see the bottleneck of your shader, as well as approximate performance with ATI/AMD cards. I don't know if it supports Nvidia cards though.