It was more of a hint of what binary you should use.
If you have a 7970 it was very likely *not* produced by Nvidia, therefore you can't use cudaHashcat-plus64.bin, but you should try w/ oclHashcat-plus64.bin
If you have a 7970 it was very likely *not* produced by Nvidia, therefore you can't use cudaHashcat-plus64.bin, but you should try w/ oclHashcat-plus64.bin