Win 7 64 bit GTX 1080 only 650 sol/s......
Thats much less then it should be. Can you give more informations, i.e. is that one card or many, with the hotfix switch enabled or without and what driver version? Until now I did not see that much difference between Windows and Linux version and thats surprisingly low for a GTX 1080

Maybe you can give us the whole command you use to start - the more information I have the easier to help you and to debug.
Some feedback for updated miner:
So far pretty stable. Been running 25 min for now no crashes but lets see if it stays alive for 24h.
6x 1070ti 0-4 gpu OC core: +150 mem: +550. gpu 4 oc core: +50 mem : +500. gpu 5 oc core: 0 mem: +400 Powerlimit: 95w
Speeds are around 13k-13k5 Sols so big upgrade from optiminer and now all gpus mine with same speeds and no hashrate drops.
Thanks for feedback! I do not have more then 2 GPU at hand for testing. Therefore nice to see that this really helps for larger rigs
The performance drops A LOT randomly, in my 1060s from 10000 to 2200 sols
Is this displayed or pool hash rate varying? The one displayed by the miner should be constant. If this is not the case then something goes wrong with the lower CPU usage fix. This one tries to sleep the CPU for a certain amount of time depending on Kernel execution. Now if system is under very high load the measured values for kernel duration may vary to much for the fix. How much CPU load do you have running all your cards simultaneously?