Only 3 cons:
1.All miners on 1 controller show up in the pools and monitor sw like Awesome Miner as 1 big device
2.Single point of failure if RasPi dies
3.When updating the MM firmware it is applied to ALL miners on the controller. NP if they all are the same model, not good if you mix say 721 and 741 miners on the 1 controller. Been there - done that and 721's don't like thinking they became 741's....
1. So, I guess from a management perspective if one miner in the chain goes down you've gotta dig into figuring out which miner is having the issue. Is that the main con?
2. Valid point, I don't really have any experience with raspi, are they generally reliable or are they more prone to failure?
3. I will have 741's only, so not an immediate issue, but good to know.
Ya. The only way to easily see the status of each miner is to use the Avalon GUI. It will ID the AUC adapters and the miners attached to them, tell you how fast each is running, etc. There you can make a miner's LED blink so you can pinpoint which is which.
Can't say I've ever had a RasPi fail but is still the Achilles heal to what can be a very large amount of hash power. Then again, easy enough to have a spare Pi already configured as you want to just plug in.
My biggest issue would be that because all the miners are reported to pools as 1 worker if there are say 10 miners on the 1 controller and 1 miner drops out or loses speed it will not be apparent for a while if you only look at the pool stats for that (huge) worker.
Thats a good point. I am also trying to think ahead about scalability issues. If i theoretically were to buy 20 of the miners and send them off to hosting, or build out my own version of a gigapod i am not sure the best way to set that up. Buy a controller for each unit? I think while i have the equipment here, locally, 4 per controller would be pretty simple.
if buy solar and I end up with say 18 741's we would use 6 rasp pi's 3x 741's per rasp pi .
this gives you spare usb to 4 pin translation dongles
along with finksy 4 k psu's 3 pieces per rasp pi is a working plan for our future build out ( if we do it)
Set 1 of 3 741'spower brick
usb cable
rasp pi
usb cable
dongle for translating usb to 4 pin signal.
four pin
avalon --1
four pin
avalon --2
four pin
avalon --3
a finksy 4k psu
------------------------------
Set 2 of 3 741'spower brick
usb cable
rasp pi
usb cable
dongle for translating usb to 4 pin signal.
four pin
avalon --1
four pin
avalon --2
four pin
avalon --3
a finksy 4k psu
------------------------------------
that dongle is hard to source.
when you buy an avalon
you get
1 dongle
1 usb
1 four pin wire
1 avalon
by using 3 to a rasp pi you conserve your translation dongles
pretty neat! 
.
