We are getting close with the serial communication software.
Let's call the current version a Beta version of the final firmware.
We have a few 10 & 12 board test setups running and after 24 hours without a hickup I can report hash rates of up to 30GH/s average per board, and this is without heatsinks.
(We also have a few test setups with an USB cable to each board, on average they do ~27GH/s)
End of next week heat sinks should arrive, and then we'll make a few test setups with higher voltages.
This firmware update is of little use for single board users.
Once you get to three or more boards it's becoming interesting.
The serial firmware has been programmed to handle up to 16 boards (target: 500GH/s @ 500W) on a single USB connection, so a lot less cable clutter.
As a side effect it will put a lot less load on the host computer running cgminer.
Using the cable connections, about 20 boards was the maximum a Raspberry with Minepeon could handle before it became noticeable (percentage of shares not accepted on the pool was rising).
We will setup a few 16 board towers and connect them all to one Raspberry this weekend, let's see when it is getting slower
We will do the same connected to a powerful Linux PC, it will be interesting to see if there is a difference in performance.
Note: We are doing all our testing with cgminer 3.12.3.
