About 4 months after marto74
announced his assembly service for avalon chips I've got my fully assembled bitcoin miner called HEX16A.
The board is based on TechnoBit's design for 16 chip miner, ordered first week of August for 49,30€ from their online shop.
My first impression of the board is the massive heatsink that covers the entire backside of the board, together with the huge filter capacitors close to the chips. Those two factors and the improved power supply module helps for the great overclocking capabilities that HEX16A provides. It can easily be clocked to 500Mhz with less than 2% HW errors, that makes the board one of the best on the market.
TehcnoBit provide their version of cgminer with support for the board and adjustable core frequency and voltage.
Here is a chart with the performance of HEX16A, keep in mind that the consumption is at the wall and includes PSU CM RS450-ACAA-D3, measured with APC SmartUPS.
Even that 500Mhz per chip is a great achievement the power drawn by the board is quite serious. If we take into account the PSU's efficiency of 85% it turns out that the board consumption is around 105W or a current of ~8.75 A. In my opinion this kind of amperage is too much for a single wire and a molex connector which by the way according to wikipedia has a max current of 11 A/pin (30 °C rise).
For comparison, ASICMINER's Blade (old version) overclocked to 13GH/s drawns 115W at the wall with the same PSU, that makes 8.84W for GH
HEX16A is equipped with 92mm cooling fan but it is lacking temperature control for it. If you value your comfort you can easily switch the fan's connector from 12 to 5V. Of course speeds higher than 400Mhz it is recommended to leave the 92mm fan at full speed. The fan itself is a SUNON EE92251S1-0000-A99 and has a great air flow of 51.5 CFM with low noise levels even at full speed: 34 dBA
At their online shop TechnoBit offer a preflashed
TP-Link TL-MR3020 with the special version of cgminer ready to use with HEX16A.
The router is based on OpenWRT firmware and provides easy to use interface to setup your mining parameters. The limited amount of RAM on the TP-Link has forced TechnoBit's developers to turn off the WiFi completely. Marto confirmed that the firmware will be open source and ready for download on their support site, so it would be great if we can manage to turn WiFi back on and use it as a client for a wireless connection.
Since this is a linux based router you can SSH into it and access the screen of cgminer with screen -r
Pros:- Price
- Overclockable to 500Mhz
- Stackable
- Cooling
- did I mentioned price
Cons:- Single molex connector, even that it's not a problem at lower clocks
Conclusion:I'm very pleased with this board, it has great overclocking potential at affordable price which can help for a faster ROI in the first months. I'm looking forward to see other products from the based in Bulgaria company TechnoBit, they are already working on BitFury and BFL based boards .
All pictures can be found here:
http://imgbox.com/g/eG0aq12mlqbest
2GOOD
Edit:
cgminer / hexminer tutorial:
https://bitcointalk.org/index.php?topic=303538.msg3371198#msg3371198