Sub.
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FYI, all, I am still waiting for my 10 singles ordered on 3/27.

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Actually this does not answer my question. The BOM linked from this wiki is incomplete. I am sure the type of buck regulator was discussed in some threads but I cannot find the information...

Based on the efficiency graph on page 6 http://www.aosmd.com/res/data_sheets/AOZ1025DI.pdf which has been measured with an AO4722 MOSFET.

What the buck regulators are used on the Icarus? What is their maximum output current per FPGA?

No. The current one is 75% efficient for a 1.2V@8A output, see page 6 of http://www.aosmd.com/res/data_sheets/AOZ1025DI.pdf

Mine is 88% efficient for the same output, see page 9: http://www.irf.com/product-info/datasheets/data/ir3840m.pdf (output voltage is adjustable just like the AOZ1025, by changing resistors).

ztex, can you please upgrade the AOZ1025 buck regulator on your designs to another able to output more than 8A to each FPGA, and more efficient? Multiple groups (eldentyrell, bitfury, etc) are writing bitstreams pushing the LX150 beyond 8A... And the AOZ1025 is not super efficient.

Perhaps the IR3840MPbF (86% efficient at 12A output at 1.2V) ?

No, Enterpoint's cairnsmore1 pre-order prices are cheaper. It will do at the very least 800 Mh/s with an average-performing bitstream (more likely 850 Mh/s) at $640. This is 1.25 Mh/s/$ (more likely 1.33 Mh/s/$). BitFury is more expensive at 1.22 Mh/s/$.

I guess one could say BitFury is cheaper on a technicality: Cairnsmore1 has not shipped yet.

Shhh! I was going to do exactly that  

It is their unverified claim. (Unverified, but plausible, given they overvolt and overclock the Spartan 6...)

Submitted to HN: http://news.ycombinator.com/item?id=4006650

My remark about sizing for 960W also applies to 240V circuits.


Actually a $10-15k pricing point is fine... The way I see it, is that as long as there are mining solutions at the following price points (orders of magnitude), anybody should be able to find something for their budget:
- around $100: entry-level/mid-level video cards.
- around $1k: quad Spartan6 boards, BFL single, etc.
- around $10k: BFL mini rig, Cairnsmore2 (hopefully).

yohan: for Cairnsmore2, please arrange the fans like rackable servers: placed at the front or back of the chassis (ie. not attached to heatsinks or FPGA boards).

My advice to you, yohan:

• Definitely use Ethernet. Not USB: the maximum cable length is only 5 meters, and large scale miners have racks spaced out my much more than 5 meters. Not cable PCIe: it is overkill, too expensive, and its extra bandwidth unnecessary.
  
• If you put an embedded PC in the unit, use USB to link it to the internal FPGA boards. You don't necessarily have to use USB cables, instead you may want to design a backplane populated with SATA data and power connectors repurposed to carry the USB signal (over the SATA data connector) and power to the FPGA boards (over the SATA power connector). The boards would be plugged into the backplane, much like a SATA drive is plugged into the SATA backplane of an x86 server. Put a USB hub controler IC on the backplane to make it a USB switch (1 upstream link to the embedded PC, multiple downstream links to the FPGA boards). A SATA power connector is only rated 4.5A for the 3.3V line, 4.5A @ 5V, and 4.5A @ 12V, therefore I would suggest to repurpose the useless 3.3V and 5V rails to 12V, giving you a total of 13.5A for 12V, or 162W per connector, which should be sufficient for a board with up to 16 LX150's. BFL seems to be following a similar idea by carrying USB signals over SATA cables (not backplane connectors though) in their mini rig.
• Use 19" rackable chassis. And make them at least 2U. Rationale: easier to cool, and bigger more efficient fans can be installed in them, compared to the 41 mm fans in 1U chassis (this is why Facebook uses 1.5U chassis in their Prineville datacenter instead of 1U: http://opencompute.org/wp/wp-content/uploads/2011/07/Server-Chassis-Specifications.pdf )
  
• Use commodity ATX power supply units. And allow users to purchase your chassis without PSUs. A lot of miners like myself have invested in efficient PSUs for their GPU rigs, and would like to re-use them. The 20/24-pin connector can power the embedded PC, while the 6- or 8-pin PCIe power connectors can power the backplane, which powers the FPGA boards.
  
• Keep it simple stupid. Fewer components means less chance of hardware failure, reduced costs, and reduced time-to-market. Particularly: (1) no LCD, and (2) no Wifi. Rationale: (1) I want to remotely configure and monitor the FPGA unit over a web interface, I don't want to deal with an LCD display and buttons that require me to be physically present in front of the unit, and (2) large miners are likely to already have cat5 deployed in their datacenters and Wifi is unreliable in some of these environments.
  
• Temperature probes for each FPGA.
  
• Fan speed monitoring (however don't necessarily make them PWM controllable)
  
• Easily replaceable fans (like some 1U chassis where fans are not screwed in, but can be slided in and out of a plastic frame, with rubber to absorb vibrations).
  
• Size each unit so that its fully-loaded configuration is about 960W. This will allow users to put exactly 2 of these units per 120V-20A circuit, or 4 per 240V-20A circuit, or 9 per 208V-30A 3-phase circuit (while not exceeding 80% of the circuit's maximum current rating). Rationale: in datacenter environments, users pay a fixed monthly price per circuit. A circuit not used at its maximum capacity (or a config not fully-loaded to not over-consume) is wasted money. BFL failed to follow this advice of mine when designing their 1250W mini rig.
  

Actually, less. Probably 65% or so.

You see 480W at the wall, but this PSU is probably outputting ~425W to the router & singles (~89% efficiency). That means 425/650 = 65%
A 650W PSU running at 100% would output exactly 650W while pulling more than 650W at the wall.

This was foresight, not hindsight.

zhoutong, these comments were relevant. You had zero excuse for being confident about Bitcoinica's security. Even if you were not running a bitcoind or managing wallets. Your site managed financial accounts with real value behind them, therefore, regardless of the implementation, these attacks and thefts were meant to happen, given you had little to no experience securing a financial website. You were warned, but you did not listen.

That said, I wish you good luck to your future endeavors.

I have 10+ for sale. You know how to contact me, we have dealt before

Meh. It is not rare, even for "professionally" designed websites, to accidentally configure the Apache manual to be accessible online...

Deal. How do you want to arrange the transaction? Email me at m.bevand at gmail.com ...

iSellBitcoins: for guidance, a fair price is roughly $400-$500 per 6990.

yochdog: offer noted, thanks, I'll think about it...

check_status: the 5870 has been sold already, sorry!

(You are likely right, but...)

You need to ask that other person to compare the SHA256 hash for his/her executable with the one you scanned.