Mini-Rig from Butterflylabs

[DeathAndTaxes]

BFL-Engineer, I would recommend to size the mini-rig either for 960W, or 1920W.
This way, either 1 or 2 could be placed on a standard 120V-20A circuit, while drawing no more than 80% of its rated capacity per the National Electric Code (1920W).

Given 99% of NEMA outlets in US residences are 15A variety why make it smaller but too large to fit on a single outlet.  Seems like the worst possible "compromise".  Keeping it under 1440W(well 1.5 KW) makes it work with virtually every outlet in the world.

Granted dedicated outlets are possible but if you are going to use dedicated outlets then current is no issue.  They could make it 5KW and it would still work fine on a 30A 240V circuit.

[1714560732]

1714560732

[silverbox]

Most circuits are 20A for outlets, Easy enuf to swap one 15A outlet wtih a Nema 5-20 to get the full 20A on one connector.

Its like a $3 dollar part at the depot.

http://www.homedepot.com/h_d1/N-25ecodZ5yc1v/R-202066702/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=20-amp

[mrb]

I am pretty sure 20A is more common than 15A, at least in all US residences built in the last few decades. My 30-year old apartment building has 20A circuits in the units. My office has 20A circuits. My previous apt had 20A circuits.

Anyway, perhaps the mini-rig should be sized for 640W. One could run 2 per 15A circuit with 160W headroom (eg. in an old residence where the circuit might be shared by a lightbulb). Or 3 per 20A circuit with no headroom (for those operating them on dedicated circuits).

[DeathAndTaxes]

Most circuits are 20A for outlets, Easy enuf to swap one 15A outlet wtih a Nema 5-20 to get the full 20A on one connector.

Its like a $3 dollar part at the depot.

http://www.homedepot.com/h_d1/N-25ecodZ5yc1v/R-202066702/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=20-amp outlet&storeId=10051

It is also a good way to start a residence fire not covered by insurance due to code violation and gross negligence.

NEMA 5-15 outlets are often wired using 14 gauge wire and connected to a 15A breaker.  Changing the outlet does nothing as the breaker will trip at 15A.  Changing the outlet and breaker is dangerous and a code violation as 14 gauge wire is only rated for 15A.  Changing the outlet, breaker, and wiring is possible but dubious.  You might as well run a dedicated circuit.  If you run a dedicated circuit going 240V makes more sense anyways.  You get double the capacity and higher efficiency.

It is possible that someone has a 15A outlet on 12 gauge wiring but that isn't the norm.  12 gauge is more expensive and builders often don't sink lots of cost into heavier wiring as it is kinda hard to sell that once the walls are up.  Suggesting they can just buy a new outlet is just reckless.  One needs to ensure the entire circuit (device, plug, outlet, wiring, and breaker) is rated for 20A.

[silverbox]

Again most outlet circuits in the US are on 20A breakers with 12 AWG romex (yellow).  Its easy enuf to check and see if its a 14 AWG romex (white), 15A breaker circuit, but usually those are lighting circuits, not outlets.  If its not 20A breaker with 12 AWG, then don't put a 5-20 outlet on it..

[silverbox]

It is possible that someone has a 15A outlet on 12 gauge wiring but that isn't the norm.  12 gauge is more expensive and builders often don't sink lots of cost into heavier wiring as it is kinda hard to sell that once the walls are up.  

This just isn't true, on a 20A circuit your allowed 13 duplex 15A outlets, whereas on a 15A circuit your only allowed 10 duplex 15A outlets.  The cost of the extra home runs with 14AWG romex on outlet circuits and the extra labor involved makes it more expensive then running 12AWG romex.  

[Epoch]

BFL-Engineer, I would recommend to size the mini-rig either for 960W, or 1920W.
This way, either 1 or 2 could be placed on a standard 120V-20A circuit, while drawing no more than 80% of its rated capacity per the National Electric Code (1920W).

While 120V@20A circuits may very well be 'standard', they are far from common in North American households. What is both standard and common is 120V@15A (1800W peak, 1440W continuous).

Targeting 120V@20A circuits would severely limit the potential market for BFL. Clearly not a good business decision.

[Inaba]

Again most outlet circuits in the US are on 20A breakers with 12 AWG romex (yellow).  Its easy enuf to check and see if its a 14 AWG romex (white), 15A breaker circuit, but usually those are lighting circuits, not outlets.  If its not 20A breaker with 12 AWG, then don't put a 5-20 outlet on it..

This is just silly.  I see very few 20A installs in existing structures and even new structures, it's somewhat rare to see anything better than 14ga 15a.  Builders are some of the cheapest mother fuckers on earth and are scum right next to car salesmen and bankers.  They aren't going to spring for 12ga wire unless absolutely necessary.  15a, 14a is the "norm."  Even if you specify 12ga, 20a, unless you watch most builders like a hawk or do it yourself, you're likely to end up with 14ga wiring.

[DeathAndTaxes]

Again most outlet circuits in the US are on 20A breakers with 12 AWG romex (yellow).  Its easy enuf to check and see if its a 14 AWG romex (white), 15A breaker circuit, but usually those are lighting circuits, not outlets.  If its not 20A breaker with 12 AWG, then don't put a 5-20 outlet on it..

This is just silly.  I see very few 20A installs in existing structures and even new structures, it's somewhat rare to see anything better than 14ga 15a.  Builders are some of the cheapest mother fuckers on earth and are scum right next to car salesmen and bankers.  They aren't going to spring for 12ga wire unless absolutely necessary.  15a, 14a is the "norm."

Exactly.  12A IS becoming more common in new construction mainly due to having more outlets in a room more desirable.  Still it is far from universal even in new construction and there are 100 million or so existing residences some with wiring 80 years old.  So I stand behind the statement that "saying just change the outlet is reckless".  

It is more like:
a) Check wiring is 12 gauge (replace if necessary).  If wiring is older than ~1970s it may not comply to any color code.  Remove section of wiring insulation to check gauge manually.
b) Ensure no other significant continual load is on the circuit (find all outlets on that circuit to verify)
c) Check breaker panel has a 20A breaker (replace if necessary)
d) Check existing outlets and ensure they don't have a current limit.  Many NEMA 5-15A outlets are not rated for 20A passthrough.  Rewire outlets using pigtails to bypass or replace all outlets on circuit if necessary
e) <Likely some more code gotcha here >
f) Go to home depot and buy that $3 outlet and replace.

f is the easy part but code compliance requires a through e.  Hardly universal or user friendly.  If BFL wanted consumer to do that they could simply keep it at 2.5 KW and require a dedicated circuit.  1440W (1.5KW is close enough) is universally compatible.

[silverbox]

Again most outlet circuits in the US are on 20A breakers with 12 AWG romex (yellow).  Its easy enuf to check and see if its a 14 AWG romex (white), 15A breaker circuit, but usually those are lighting circuits, not outlets.  If its not 20A breaker with 12 AWG, then don't put a 5-20 outlet on it..

This is just silly.  I see very few 20A installs in existing structures and even new structures, it's somewhat rare to see anything better than 14ga 15a.  Builders are some of the cheapest mother fuckers on earth and are scum right next to car salesmen and bankers.  They aren't going to spring for 12ga wire unless absolutely necessary.  15a, 14a is the "norm."  Even if you specify 12ga, 20a, unless you watch most builders like a hawk or do it yourself, you're likely to end up with 14ga wiring.

I used to build custom houses (when there was a boom), lately its been additions and remodels.  I use yellow 12ga for everything.  I see more 20A outlet circuits then 15A, but hey i'm in California, most of our houses were built fairly recently, back east it might be a different story.  Knob and tube is probably still the standard back there eh?

[Glasswalker]

I would like to pitch in on the idea for doing a blade server type approach.

Sell a chassis for something like $5K and then have inexpensive blades that can be added over time to increase hashing power. (up to a total price, fully populated of $15K for 25GHash of mining power roughly). This approach will open you up to a much larger market space, and allow people to ease into the investment more smoothly. Large one time investments tend to shatter the growth curve because of the significant cycle time between growth spurts. Solutions allowing constant growth provide a sharper growth curve, and better ROI to owners.

[siggy]

Really guys?  You're going to base your purchase decision on "can I fit 1 or 2 or 3 on a 15/20 amp circuit" ..??   We're talking $15,000 here .. If you have a doubt, bring in an electrician to run a dedicated circuit.

[JWU42]

Really guys?  You're going to base your purchase decision on "can I fit 1 or 2 or 3 on a 15/20 amp circuit" ..??   We're talking $15,000 here .. If you have a doubt, bring in an electrician to run a dedicated circuit.

Amen brother...

I have 4 20amp dedicated circuits just waiting 

[triplehelix]

we had a kitchen fire last month.  we are first floor apartment in a two family home.  the house is about 100 years old.  the kitchen in our apartment was redone approximately 20 years ago.  the drywall isn't up yet, and after reading this thread i went and took a look at the wiring.

the wiring that existed prior to the fire, both to my apartment and the wiring traveling to the upstairs residence, as well as the new wiring installed by the contracter doing the repairs, is all 12 gauge.

too small a sample size to draw any conclusions, but there you go.

[Inaba]

Usually a remodel will have better wiring.  New construction by builders = as cheap as they can possibly get without setting fire to the place prior to sale.  After sale = who cares!

[rjk]

Usually a remodel will have better wiring.  New construction by builders = as cheap as they can possibly get without setting fire to the place prior to sale.  After sale = who cares!

+1 for cookie cutter boxes, but many custom builders are a little more careful. I've experienced both, and unfortunately many of the inexpensive remodels are 14 with a mixture of knob and tube in some shoddy bungalows. Most of the build to order houses near me are all done up with 12 everywhere. Some (including ours) even have a 400 amp service entrance.

[Cablez]

All of the different apartments that I have lived in for the last 10 years (5+) were all 15A 14gauge circuits for receptacles and lighting.  The only 20A 12gauge circuits I have come across have been for specialized appliances (i.e. stoves, refrigerators, fake furnaces, etc). 

I would also suggest that BFL keep the wattage to fit on 15A circuits for a more mainstream application.

[tgmarks]

I don't know about doing exactly what glasswalker described with a blade server, but I think he had the right idea in it being some type of modular design with a main board and housing.  I like the idea of this a lot, but $15k is a little hard for me to swallow right off the bat.

[JWU42]

Forgot to mention I applaud BFL for coming up with an offering (potentially) to compete price wise with LargeCoin...

[mrb]

Really guys?  You're going to base your purchase decision on "can I fit 1 or 2 or 3 on a 15/20 amp circuit" ..??   We're talking $15,000 here .. If you have a doubt, bring in an electrician to run a dedicated circuit.

It is about maximum utilization, and efficiency.

It does not matter if you buy only 1 rig. But the larger your scale, the more you should care about these details.

I would rather spend 1 or 2 grands in mining hardware than in installing extra circuits because the BFL designers chose an awkward wattage that prevents me from utilizing my circuits to their maximum capacity.