I'm no expert but have built a few pc gaming systems in my time. Please correct me if I'm wrong..
Even though BFL labs state, "PCI Express - Monarch cards consume two PCI slots when installed in a standard ATX montherboard. The PCIe format used is 1X for maximum compatibility.", does this not mean that they will use the pci-e x16 slot (not to be confused with a pci-e x1 slot) and run it as pci-e x1 in the bios? Would this not make both the images and their reference to pci-e x 1 marry up?
It means they will use a PCI-E x1 connector (as they should), because the
x1 bandwidth is more than enough for bitcoin mining. You can slot a PCI-E x1 card in any x1, x4, x8 or x16 slot.
You can also use a PCI-E x16 card (GPU) to mine on PCI-E x1, this is a known trick way back into 2011 at least, for example,
https://bitcointalksearch.org/topic/pcie-x1-capable-of-transmitting-video-or-only-mining-6982Also the power connectors are not visible in the four images because none of the images show that side of the card? If we argue that the first image does, then it's fair to say this BFL card doesn't have any power connectors.
The first image of the card shows enough to see there are no power connectors there (it's a CAD oversight no doubts there). You need
two 8-pin PCI-E power connectors to be able to reach 350W+.
I'm not sure how accurate your stats are for power draw as according this source you can see a 7970 uses 362 watts, with the 7990 drawing 491 watts.
http://www.techspot.com/review/663-amd-radeon-hd-7990/page8.htmlIn terms of the air cooling solution, what I see in those images is no different to high end dual slot gpu's not using after market cooling.
All that said you would be mad to go for one of these cards from BFL. I hope they get their arses kicked by NY Department of Financial Sevices.
EDIT: I thought I was mistaken by the link mentioning 'system power consumption' meaning entire sytem but it's not, it is indeed the cards only.
Those pics show
total system power, a 7970 GHz edition there would be consuming at max 362-74 = 288W (which it isn't because there's also CPU+RAM load on the Crysis 3 stress test). You can check that the official
TDP of the 7970 is 250W.
Keep in mind that their goal is to go for an
external exhaust card to be used on 4U cases. External exhaust cards blow all the hot air to the outside of the case so that you mostly only need to worry about intake fans for cool air.
A 7990, for example (as all dual GPU cards) use cooling solutions that leave a lot of hot air inside, and this hot air re-circulation is what makes it very difficult to have 3 cards inside one case, because now you need intake fans and outake fans capable of removing all that excess heat. Also, let's not forget that a 7990 at 375W TDP is actually two chips (~187.5W each), so I'd say BFL will probably use a solution with several chips inside.
In the end, if they want to keep an EE solution (and they should) they will probably have to lower specs on the cards to ~250W total each (underclocking/undervolting/less chips per card) for the EE cooling to be effective.