Hashfast can we get an official word on this?  While not stated in the original MPP terms if shipment is delayed it would provide some partial assurance if that event doesn't also delay the MPP.  Can the company consider having the 90 day window for MPP begin 1 Nov regardless of actual unit shipment date (with computed return towards break even beginning based on actual shipment date).  Just one way HashFast can show they are the professional choice.

HashFast have the final PCB been produced?  If so can we see some photos?  
I am interested in final dimensions, locations of power connectors, etc.

An extension of this is that damages in a court of law are awarded in legal tender.

So someone borrows 100 BTC fails to repay and you sue them.  Assumming the court agrees that the debt is valid they will enter a judgement in legal tender so if the current exchange rate is $200 USD per BTC the court might award a judgement of $20,000.   You may collect the value of your damages but you have no guarantee it will be paid in anything other than legal tender.

I don't believe HF is selling a control unit seperately the 1U control unit is simply a "free" upgrade if you buy 10 Sierras (nicely fills an entire rack).

The Sierras have a single USB port connection on the back.  Any system (capable of running cgminer) can be used as a host/controller.  There isn't anything particularly special about the "1U controller" it is simply an entry level 1U server.  You could buy your own "off the shelf".  Even an Atom server w/ 2GB of RAM likely more than enough computer "oomph" to run cgminer for as many modules as you want to connect.  If you have more Sierras than USB ports just use a USB hub.

Even if it isn't available for sale maybe HF can share the specs (processor, RAM, HDD, etc) for the controller to help customers find an equivalent.

Still I imagine the requirements are modest.  This is likely overkill.
http://www.newegg.com/Product/Product.aspx?Item=N82E16816101365

Does v0.9.5 improve or worsen power consumption at the wall?

This.  The often misquoted Gresham's if often misquoted to mean "bad money displaces good money" but this important caveat is UNDER GOVERNMENTAL FORCE.  As for spenders it makes sense.  I have this dollar I don't trust and I have this lump of gold I do trust.  I will save the gold and spend the dollar.   However if one thinks a little deeper if logically one wants to keep gold and get rid of dollars why would a merchant accept dollars.  Maybe they would in a limited fashion to quickly exchange the dollar for gold and pawn the risk on some other sucker but if everyone is doing that then essentially there is no market for the bad money.  However Gresham's law is pointing out that if the government makes the bad money legal tender and thus obligating its acceptance is certain scenarios then the better money is displaced.   Without the government using force people would simply demand the better money (gold) or at a minimum charge a higher price for payment in the bad money.

The same could be said of all current, future and past currencies the only difference is the size of the "flock of enthusiasts".

What encryption?

Yup still have some left.  Never used, original in box.  DD made a batch of them specifically for me because no stores were stocking them at the time and I needed like 40 but their min order was 50 units so I have some left over.

I will post some  photos tonight if you want but it looks just like the store link above.  $60 for one plus actual S&H (first class or priority mail) or $100 for two w/ free shipping (priority mail).   Buy two and get a used 5970 for double the fun. 

Paid in BTC using bitstamp rate at time of payment.  Let me know.

Contracting for a lower price by agreeing to a volume is pretty common in the business world.  Both sides win (and likely have compensation if agreement is not lived up to).  No need for a custom unit if stock units fill the need.

One "issue" (only for a moder) with those preconfigured waterloops is generally they are sealed systems.  You can't add an extra waterblock.  So while the unit can handle 900W of heat you couldn't connect 3 waterblocks to it.  Still based on the dimensions it does look like HF could use two waterloops like that to cool 4 boards per chassis (call it a 4 module Sierra or maybe give it a new name).   Lots of interesting options.

I (maybe a minority) am more interested in a custom solution.  Single large radiator, separate pump, separate reservoir and the ability to custom built a different solution.  Using two "server" style power supplies (they tend to be thinner) one could maybe put 6 modules in a single chassis (4U). 

Thanks for all the technical details Simon it certainly clears up a lot of stuff.   I agree on the choice of PSU vendor.  Used SeaSonics to power a GPU farm and they worked flawlessly at high load in brutal conditions.

BTW any plans to sell just "naked boards"?

I may still have a couple (unused in original package).  Danger Den brand.  I will take a look tomorrow morning.

It is this model (full body water block covers VRMs, GPU cores):
http://www.dangerden.com/store/dd-5970-water-block.html

Makes sense is it is reasonably powerful unit (for off the shelf stock) and it is self cointained which makes bulk assembly easier.   Still I do hope HF makes "naked boards" available.   The H80i isn't exactly cheap at $80.  Even if HF is getting an unbranded version for coolit for say $60 each there are three and that is a significant cost point to the total sytstem cost.  I guesstimate the case at $60.  If the power supply is 2x 660W they are $150 ea (if larger it will be even more).  Toss in two intake fans at lets say $10 ea.   So the balance of system cost in a Sierra the non-ASIC costs is are something like $600 (60 x 3 + $60 + $150 x 2 + $10 x2 = $560, round up to $600 for reduced labor and packaging).  Sierra's current pricing w/o MPP is $6,300 so knock $600 off and it would be ~$5,700 for 3 naked modules or $1,900 ea (maybe $1,500 ea in bulk)?   Sell them as naked modules and let the community come up with innovative solutions.

Well failover implies each PSU can handle the full load and that isn't confirmed.   Expansion is improbable given the dimensions of the chassis.   To their credit HF used the available space pretty well.  I don't see you putting another module plus fan/radiator/pump combo in there without extensive redesign.  Might be an interesting project.

They also accept bank wires.

I would certainly hope the Sierra doesn't require 1400W DC.  That would be ~1500W AC and would make the efficiency worse than 1.2 J/GH.  Given that 55nm Bitfury does less than 0.9 J/GH at the wall and KNC does less than 1.1 J/GH I would be hoping for something more.

The stated efficiency of BabyJet is 350W at the wall or 0.88 J/GH.  Assume a 90% efficienct PSU that would mean 350W AC is 315W DC.  Three times that is ~950W DC.   Seems that either a single 1000W Platinum or 1250W Gold PSU should be fine.

For the record, at the high end SeaSonic only has 860W & 1000W PSU Platinum models and 860W, 1000W, and 1250W Gold models.

One edit:
one thing I hadn't considered is that HF may be saving cost by using a single model PSU across products.   Say the BabyJet comes with 660W PSU.  Rather than stock a different model the Sierra comes with 2x 660W PSUs.  Note the above is just my theorizing.

Why two power supplies?  How are 3 modules connected to two power supplies?  Are they producing redundancy?  If so how is that achieved? Is each power supply connected to each board (would imply two power connections pwe board)?  Wouldn't one large power supply be sufficient, cheaper, and take up less space?

Yeah it does seem confusing.   I can't see any reason for the second power supply.

One new thing is notice the usb port above the left power supply.  It looks like it connects to one of the boards.  So single usb port to board #1 and the boards 2 & 3 daisy chained off it.

As for a 4th module you could certainly mount a board but where are you going to put the watercooling radiator?



HF is the same water cooling radiator used for BabyJet with obviously only 1 used (2 if upgrade module is installed)?

Nobody knows for sure but I think 10 PH/s if a good estimate of 2013 pre-orders.   If everyone delivers by Jan we can expect difficulty to quadruple between now and then.  Honestly it doesn't really matter if there is a "slow week" if the following week is some 800 TH/s rollout.

Plan on 10 PH/s in January and adjust your coinflow accordingly.