I've seen that a Processor Pack is available for Visual Studio 6, however it appears to only be available for users with SP5 and I am already using SP6:
In addition, the Visual C++ Processor Pack (VCPP) was removed from Service Pack 6. If you have the VCPP installed, installing SP6 will remove it from your machine. If you wish to continue using the VCPP, you will need to stay with SP5 or migrate to Visual Studio 2002 or 2003 (recommended).
Firstly, is this processor pack compatible with Visual Studio 6 SP6?
Secondly, would it actually help me? I'm concerned about getting the most from my application, but it needs to run on all flavours of Intel and AMD chips so I can't just target one platform.