After reading all this thread and learn, now I have 2 AntMiners working at 3.0 Gh.
With out of the box AntMiner, step by step i change the clock parameter to 0881 (1.8Gh), after that value i collect many HW errors, so i add R2 10K and change R1 with 3.3K (dismounted from a cd drive board).
Now all the errors disappear but the ant miner became really hot, i mount it on a dissipator (2.9 °C/W) dismounting the original one leaving the rubber and smearing thermal silicone grease, the coil also was hot (50°C).
http://i58.tinypic.com/34fbjvo.jpgNow the ant miner works without errors till 0A81 (2.2 Gh).
Pushing up the frequency the coil and the asic increase their heat.
At this point i decide to dissipate also this heat. I cut a piece of aluminium and another squared piece for the asic (8x8 mm and 2mm thick) for equilibrate the different heights of coil and chip.
http://i57.tinypic.com/zvg2d.jpgRemember to put always thermal silicone grease.
http://i58.tinypic.com/wrc2mw.jpgNow i try to increase the frequency till 4E81 (3.0 Gh) without HW errors.
http://i62.tinypic.com/359aelc.jpgAfter all i discover that also the power chip is hot (70 °C), so decide to put a little piece of aluminium with grease on top of it glued (cyanoacrylate) on the aluminium.
http://i62.tinypic.com/nv4ino.jpgI use an UsbHub with 4A power supply limited at 1A for each port, but the real voltage on usb ports is 4.52 Volts.
The software is BFGMINER 3.10.0 and the OS is Open Suse.
I insert also inside the conf the icarus-timing with the right Hs value extracted launching miner.php on the web server (Apache 2).
Now for me is enough. Thanks all.
My bfgminer.conf
{
"pools" : [
{
"url" : "stratum+tcp://stratum.bitcoin.cz:3333",
"user" : "user.user",
"pass" : "xxxxxx",
"pool-priority" : "0"
},
{
"url" : "stratum+tcp://us1.eclipsemc.com:3333",
"user" : "user.user",
"pass" : "yyyyyy",
"pool-priority" : "1"
}
]
,
"api-listen" : true,
"api-mcast-port" : "4028",
"api-port" : "4028",
"expiry" : "120",
"expiry-lp" : "3600",
"log" : "5",
"no-pool-disable" : true,
"no-show-processors" : true,
"no-show-procs" : true,
"no-unicode" : true,
"queue" : "2",
"scan-time" : "60",
"skip-security-checks" : "0",
"submit-stale" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/share/bfgminer",
"scan" : [
"antminer:all"
],
"set-device" : [
"antminer:clock=x4E81"
],
"api-allow" : "W:192.168.1.0/24",
"icarus-options" : "115200:2:2",
"icarus-timing" : "0.153"
}
http://i62.tinypic.com/30w3z48.jpg