thanks marto,
you did a great work in regard of overclocking!

hex16 running at 450MHz (52°C on asic, ~90W, 1350mV, 7GH, 1-2% HW erorrs) quite well,
500MHz works but a little bit hot (63°C on asic, ~110W, 1460mV, 7,6GH, 2-3% HW errors).
510MHz (1440mV) works, but hw errors go up.

1500mv has not worked. try undervolting the suggestions from:
https://bitcointalk.org/index.php?topic=303538.0


is there a temp sensor or at least a overheat protection at the board?
(if not - I will build something external)

if you see problems with more than 1 hex16a on cgminer startup - get a better hub! specially "genesis" usb hub chip seems to be bad.
symptomes: after usb device reset by cgminer it never comes back, in dmesg you see many usb errors
I use a raspberry pi as with cgminer 3.6.6.

try to use a power-cable for each hex16, I had quite hot cables when running 3 of them at a wire; also hw errors goes up because of voltage drop.
I use a corsair 650tx power supply for 5 miners, connected to the 2 pcie plugs.


used power connector from an old mainboard:
http://upload.confusion.at/bt/power.jpg

mounted the hex16a like a tunnel in a old pc case; one fan on each side, so one fan could die
http://upload.confusion.at/bt/case.jpg