it's got the same SMX configuration as my 780 Ti which does 450 kHash/s

so try -l T30x16

raise the TDP limit to 106% using overclocking tools (if these work with Quadro cards...), possibly also raise the core + mem clock.

Use the -C1 or -C2 flags on the K5000 card.

don't forget to specify -H 2 for lower CPU utilization, and -i 0 for maximum GPU utilization (even if that induces some lag on the desktop, if the card also drives your monitor)