<p>We have a graphics intensive application that seems to be experiencing problems on AMD 64 bit Dual Core platforms that are not apparent on Intel platforms.</p>

<p>Running the application causes the CPU to run at 100%, in particular when using code for shadows and lighting (Open GL).</p>

<p>Does anyone know of specific issues with AMD processors that could cause this or know where to track down the problem, and/or ways to optimize the code base to avoid these issues?</p>

<p><em>note, the application generally works well on mid range hardware, my dev machine has an nvidia gtx260 card in, so lack of power should not be an issue</em></p>

I would invest in profiling software to trace down the actual cause of the problem.
On linux, Valgrind ( which contains Cachegrind &  Callgrind ) + KCacheGrind can make working out where all the heavy function calls are going on.
Also, compile with full debug symbols and it can even show the assembley code at the slow function calls.
If you're using an Intel Specific compiler, this may be part of your problem ( not definate tho ), and try the GCC family.
Also, you may want to dive into OpenMP and Threads if you haven't already.