I get 230-250 khash/s on my standard 2GB GTX670. Does this sound about average  for a 670?

I have gpu core clocked +100MHz and memory at 1550MHz.

My settings are -i 1 -l K7x32  -C 1 -H 1

K14x16 works well but K7x32 seems to be more consistently high.

I use -i 1 because 0 makes my PC stutter too much. I need that extra power for general usage.

Using -auto always results in a statement saying the results would yield something like 300khash+ but when I run the settings it suggests, I just get 100khash or so.

Also, does memory amount on gpu matter? Cudaminer is only using half of the 2GB available. How do I adjust the memory usage? I thought more memory helps mining.