GTX 670 Low Hash Rate
I am looking for a bit of help here.

I have a GTX 670 2GB running on Windows 10 64bit, I installed the Cuda 9.1 Developer Packackage. 

For Some reason, the hashrate is a low 140h/s but many benchmark sites claim that the card is capable of hashing in the mid to high 300's . Any idea of what I need to do to get hashing at the higher rates? I have access to a lot of these cards and if I can get it to work out, it would be good.

Any sample config file setting would help a great deal. Thanks!