Got notice last night from Bitmain that my b3 has shipped. Literally about 7hrs after they confirmed payment. 

Problem with letting the dust bunnies start living in the miners is not just one of them restricting airflow. Surface contamination of the heatsink fins by fine dust rather dramatically begins to impact heat xfr efficiency before airflow throttling becomes a concern. Miners like all the cooling they can get. Yes, they can tolerate what I would call heavy abuse and possibly/probably do it for a rather long time.

But still, when so easy to kill 2 birds with 1 stone...

From the highest yardarm matey with"them" being the designers

Missed that somehow. Good info to work with.
Still keeping at 600 though as that hottest board is also what generates the most HW errors. Below 100C it's less than a total of 1 HW error every 500 accepted shares with almost all coming from that 1 card. At higher freq and temp 102-103C the errors from that card alone were 1 error every 75 accepted shares. yeesh...

ref https://bitcointalk.org/index.php?topic=1512186.msg15212835#msg15212835
I've dropped my b1 down to 600MHz to keep temp of the hot board under 100C with the ambient in my basement being around 85F.

or more. There's what, 21 sets of data cable connector pads? ... As I mentioned elsewhere, 2 s9 blades in a reused s7 case should make the thermal issue a moot point...

So far, even having to down clock my b1 (now in my rather warm basement) to 600MHz to keep temps reasonable still liking them and looking forward to my b3.

Now only question is what to do with the s7's I have piling up as I take them off line to stay within my available power budgets.  Got 5x 'spares' so far.... 

@ Sidehack - got power available for a couple s7's say directly pointed at your wallet (to pay for the electric) for you to play with optimizing?

yes.
The history of large monolithic mining ASIC's like the Minion (Hashfast?) or BFL's Monarch chips with lots of cores/pipelines/engines/ whatever ya want to call them, let's stick to 'cores', is a travesty of wasted and stolen money (pre-order$). Whoever did the designs for those and others had no idea about feeding power to and removing heat from those chips. Purely an afterthought. Hell even on 'small' chips Bitmine.ch kept trying to use little stick-on chipsinks for their A1 (and of course having many fall off, burn off). It took the Dragon and clones of it to show them that ya need serious sinks for the top...

With proper attention from the start to even just those 2 points (with #1 being feeding clean power to the logic in the chip) the idea does have merit.

Hmm, possibly do it with several internal banks of string config cores perhaps? Lets ya raise the voltage and drop the current needs vs running all them cores in parallel at low Vc/Massive current... Okay, if a mining chip maker tries it, you 1st read of the idea here from me.....

In the USA Customs Duty/import tax does not kick in until the value of the shipment (or goods you bring in from a trip abroad) exceeds $2500.

As long as the filter material has fairly large open cells and you knock the dust off every so often it makes very little if any difference in temps even on my s9.

Solo or in a pool? If solo -- cha ching with near instant ROI!

According to Kano the network has been pretty much on schedule. Last block found 9min ago as of this post.
However - I made my buy at 11:00a and so far just over 4hrs later no acknowledgement from Bitmain.

So far in the past they have eventually confirmed payment when a delay like this happens but still...  <worried>

edit: the tx finally cleared and got conf from Bitmain. 6hrs after sending from my wallet and with Blockchain already having showed >12 block conf's when I had checked 4-hrs into the wait for confirmation from Bitmain on the tx, but done.

Also note that it has the same # of chips as b1 (189) but runs at a lower clock of 600MHz. Looks like Bitmain decided that the b1's were actually now what they consider as OC'd... Their way of addressing the high chip temps?

Und ja, I ordered 1 of the batch-3's.

Oh, my b1 miner seems to have settled down in it's new home and the overnight avg hash rate as reported by Kano is 13.5THs and checking just now is holding at 13.7 average on the gui. Much better than the barely 13THs it started out at.

I'd go with the 1/4" thick stuff  which is what I used.

re-read my post https://bitcointalk.org/index.php?topic=1512186.msg15212835#msg15212835 for the edit about that... The effectiveness varies with fan speed but helped immensely here. Should apply to s7's as well.

For industrial scale btc farms and other large blockchain processing concerns ja it might if IBM & friends could be talked into it. BW's dealling with Samsung may or may not help there. The peta farms are the only ones with large enough equipment turnover and certainty of where the gear is at (ownership) to make it worthwhile. For us lowly 'small' miners best we can do is the recycle yard or pass-it-down resale.

And and since the control board has them tantalizing unpopulated pads for data connectors, filling them, getting some long data cable and then reuse old s7 cases for 2 s9 blades each...

Would certainly solve the airflow problem.

Hmm, wonder if I could fit an English Wheel (metal panel forming tool) through the case to bow out the top-sink side? think think think...

I'll leave other to post pics. Got mine today and so far am - happy - with it but...
A. is so far averaging just over 13THs
B. A thermal design issue raises it head with these. The middle card and the one with long finned heatsinks facing the case wall run well over 4.3-.5 THs each. They report chip temps of around 90C. The one with the short fin topsinks facing the case is giving a bit over 3THs and reports the chip temp as banging around 99-100C. The air coming out of that card is also substantially warmer than the other 2. Will measure temps tomorrow sometime.

The root problem is that the short sinks are presenting a much high airflow resistance because the flow channel is restricted by them and the case wall. If somehow move the cards over a smig, hell even 1/8" might do it, then airflow should remarkably improve.

edit: Also, mine wants to be a howler but I found a way to mitigate/highly reduce the siren effect: Put a square piece of open cell foam (air filter kind) over the grill of the intake fan. Suction will hold it fine but a touch of glue/tape whatever wouldn't hurt. Anywho -- it disrupts the airflow just enough that volia' howling gone.

Of course your mileage may vary