What hardware do I need to speed up generation of address, it uses GPU?
vanitygen.exe is using CPU but the same file from samr7 contains also
oclvanitygen.exe which is using GPU:
You can try vanitygen.exe or use the file oclvanitygen.exe, its up to you which one you prefer. The difference between them is that vanitygen is CPU-based and oclvanitygen GPU-based. For our 4-digit combination, dont matter if case-sensitive or case-insensitive, vanitygen is sufficient on a normal PC, oclvanitygen tends to be faster, if it works. For the technical background you'll find more information in the original article from 2011:
https://bitcointalk.org/index.php?topic=25804.0
But after I created the guide, Jean_Luc developed VanitySearch which is much faster in general. So if you need more than 4 characters, VanitySearch is your best decision: