"now compiling for compute 1.0" does not give higher results on Fermi on Ubuntu 12.04

[biozshock]

Have GeForce GTX 560, ubuntu 12.04 and Cuda 5.5. If i change Makefile manually to use -arch=compute_20 then hashrate goes up from approx 95 khash/s to about 115 khash/s. So maybe it worth it to tune this? Both versions run with -i 1 -H 1 -l F11x8 -C 1