- What percentage of my CPU horsepower can I expect the encoding to consume
- Where can I get running software, exe or source code, for doing this
- I want to make sure it takes advantage of [new] instructions in the i7 to accelerate this task
- Is there a particular compiler or IDE that will yield more efficient results
The Intel Media SDK may be of interest to you because its designed to leverage the capabilities of the GPU to perform rapid encoding. In most cases the CPU load is negligible. The encoder link that you referenced is part of the Media SDK Samples.
I recommend downloading the SDK: http://software.intel.com/en-us/articles/vcsource-tools-media-sdk/ and checking out the documentation. Given the few requirements that you listed, I think the Intel Media SDK may be the right direction.