1080 TI FE, poor performance

Hey everyone, mining noob here. I'm trying to find the best overall configuration (overclock, miner, pool etc) to use to get the best performance out of my 1080 TI FE.

I see people getting 700+ sols/s and I don't understand what it is I'm doing wrong.

Here's what I have, and how it's set up as of right now:

EVGA X58 motherboard, intel i7 980x, 12gb DDR3-1600 ram
MSI GTX 1080 TI FE, overclocked:
- Power Target, 120%
- Thermal Target, 90 deg
- GPU offset, +175 (Total clock is running @ 2050 rock solid)
- MEM offset, +500 (Total mem clock is running @ 5508 rock solid)
- Fans @ 100% to avoid any doubt, Temps @ 59 deg rock solid

I'm running NiceHash Miner v1.7.5.13, I'm on the latest GeForce drivers. Here's an excerpt of my Z-Cash stats:

[12:39:01][0x00000e20][info] =====> 270.826667 H/s
[12:39:01][0x00000e20][info] gpuinfo | GPU#0 TEMP: 59 C USAGE: 100 % MEMCTRL: 30 % POWER: 173.339 W
[12:39:01][0x00000e20][info] =====> Total power: 173.339W Efficiency: 1.562410

Any help would be greatly appreciated. Thanks!

I forgot to mention my OS: Windows 10 LTSB (Long Term Service Branch)

True story, just did a reboot, it applied a windows update (unsure which one as of right now) redid the overclock. Cleared benchmark and re-benched... 690-697 Sols/s very strange...