I'm up and running with 8 cards under windows with no issues. I never did anything in the BIOS except tell it to boot from USB the first time to do the windows install. I downloaded the latest ISO directly from Microsoft, stripped out all the bloat to make a light "miner" version. I then installed into 120GB Msata from USB using the built in VGA port. Once it was installed, I let it go out and grab all the latest updates.
I then installed a single GPU and installed the latest Nvidia drivers (all done with VGA monitor still connected to the mobo). Once that was done, I shut down and added 7 more cards and started back up again. It took Windows about 20 minutes to properly see and load the drivers for those additional 7 GPUs. Once that was done, I installed Afterburner, Afterburner Remote Server and Awesome Miner Remote Agent.
Went into Awesome Miner on my workstation, added the Octominer, and away I went mining. Very smooth from start to finish.
Hashing away with nice low temps despite running with no lid:
And some pics of the rig. I'm running a 2400W Delta PSU temporarily until I decide what I want to put in it. I'm also running 4 hybrid 1070's for right now since they needed a home and I'm still waiting on some other mobos to come in. It will be converted to all air cards soon, but I didn't want to leave any cards sitting around not hashing.
I'm overall pleased with the Octominer, but do have a few minor gripes as follows:
1. The silk screen showing the front panel pin-out is obscured by the mSATA device.
2. The polarity for the front panel HDD header is missing.
3. The Delta fans are nice 4 wire (PWM control), but both the RPM and PWM wires were cut off, leaving only GND and 12V. It would have been nice if those wires had been left intact in case I wanted to ever use those fans in another application. A 4-pin fan header to 2-pin Molex plug would have been ideal.
4. There is no provisionings for screwing down the Octominer server PSU within the "ATX PSU" space.
I know, very miner gripes, but I wanted to mention them. The key thing is that the board itself is very stable and works well, even with Windows. The board was able to to detect my Logitech USB Bluetooth dongle for my wireless keyboard and mouse, something that I cannot say was true with either my Onda nor Coloful mobos.