The main reason for KNC not including a PSU was that shipping PSUs across borders can cause unforeseen delays due to regulatory security requirements regarding power supplies.
As a customer you are paying for the PSU either way. Even if it's included in the price it's still the customer's money.

Edit: I'm not saying that HashFast is doing something wrong by including the PSU, just saying that I don't see much of a point in this statement.

Oh, I don't disagree. I'm just laughing at the idea of saying that Hashfast is picking up the tab on the power supply. It's like Ferrari saying that a new version of the 458 Spider has 20 more HP, and that's great for customers because Ferrari is picking up the tab for the engine.

HashFast likely made a good engineering choice there, but the customers are still the ones picking up the tab for it.

For our mining rigs we have chosen to specify power supplies that are rated 20% higher than the highest wattage we expect even including significant overclocking. The GN chip uses 250W at nominal, and we have designed all the systems to handle upto 350W. When the mini motherboard is supplying 350W to the chip (this level of overclock should result in up to 540GH/s) the mini motherboard may consume up to 411W of 12v, due to losses in the VRM. Add 25W for fans, and you get to 436W per mini-motherboard. Multiply by 3 chips in the Sierra, and you get about 1300W. We've added a safety margin of 20% extra on top of this - so we needed power supplies that were rated to a minimum of 1560W @ 12v to meet these specifications, and maintain the headroom and margin we desired to ensure reliable, efficient long term operation.

There are very few manufacturers who make single 1600W supplies, and we didn't find a single unit from a high quality vendor. In addition this size of supply is more expensive than 2 smaller supplies. The Sea Sonic supplies are really well built, and even significantly overbuilt. In all tests they are capable of supplying power well above their ratings, and the output regulation is very accurate and smooth. They handle hot operating environments very well. Please go read the reviews of the supplies in the Sierra - the Sea Sonic X-850FM3.

http://hardocp.com/article/2013/04/04/seasonic_xseries_x850_power_supply_review/9#.UmDCKVCcc5g
http://www.kitguru.net/components/power-supplies/zardon/seasonic-x-series-850w-km3-power-supply-review/7/

Each GN chip is on it's own mini-motherboard, and each mini-motherboard has 2 separate 6 pin PCI-E power connectors. Each of the supplies feeds 3 of these connectors.

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.

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.

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)?

Sucks being caught in a lie, huh?   Just promise to stick around & let me gawk.  Don't vanish as soon as it dawns on you that while you were conning everyone else, you've got suckered too.  
Pre-ordered my popcorn from your competition, don't make me waste it

My beef is the amount of boldfaced lying that goes on on this forum.  People like you shit up bitcoin for the rest of us, GET IT?

So no chips.  You do realize that most of the world interprets "chips by October 17" to mean "on or before," right?  The window *closes* on the 17th, it is no longer open.  Seventeenth is *the latest*.

Learn to spin better or stop.

Ohai Cypher!  Remember this?  https://bitcointalk.org/index.php?topic=270384.msg3267143#msg3267143

"HF is still on track to get chips by October 17 and that is by TSMC's estimate, not HF's"

What's up -- every question is interesting but the one about the chips showing up (or "silicone," as me & Amy call 'em )

I'll have to open a scam accusation if you don't reply.

I like how you compare the blockchain and germline (depicted as DNA). As a Biologist I always see a lot of parallels between the two.

No, you would actually have to convince the Bitcoin users to switch to a Bitcoin version not accepting those coins. If you manage to convince nearly all of them, it would work and screw up all that didn't follow. If you only manage to convince a lot (e.g. 60%) it would create chaos.