Mini-Rig from Butterflylabs - page 10.

silverbox

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Quote from: DeathAndTaxes on March 20, 2012, 12:48:24 PM

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.

silverbox

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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..

DeathAndTaxes

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Gerald Davis

Quote from: silverbox on March 20, 2012, 12:41:38 PM

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.

mrb

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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).

silverbox

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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

DeathAndTaxes

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Gerald Davis

Quote from: mrb on March 20, 2012, 12:30:26 PM

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.

mrb

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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).

finway

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What a crazy world! Cry

kjlimo

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I'm increasingly talking with co-workers & friends to get an investment club to buy one of these things...

However, I feel like I would want to fly to Butterfly labs and negotiate in person. For a purchase of $15,000 or $30,000 for two, I would want to have a one on one meeting to discuss delivery timing and expectations.

If they have enough random people buying them online with no interaction other than e-mail, then I guess they don't need my money, but this would be a condition of mine before I put my (and my friend's) money down.

dave3

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It's unlikely I'd purchase one, but I do think it's a good idea for those interested in larger systems.

I'll go for a small cluster of Singles (but probably no more than 10-12).

PulsedMedia

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Quote from: BlackPrapor on March 19, 2012, 09:55:02 AM

You're right, but paying double price for a few more % is ridiculous at least (I'm talking about Platinum series PSU's)

Let's assume system with 6x7970 underclocked and undervolted, that is something like 900-1000W usage, let's say 1kW exact.

Enermax platinum costs 330$ for 1200W unit, and seasonic costs 270$
They are running at 83% load.

Enermax report: http://www.plugloadsolutions.com/psu_reports/ENERMAX_EPM1200EWT_ECOS%202585_1200W_Report.pdf
Enermax is actually above 90% still on this load, let's say it's close to it's average of 90.62% at 90.3%

So let's say seasonic does 89.6% (load just above 80% so take just a notch off from 89.9%)

Seasonic usage: 1116W
Enermax usage: 1107W

It's less than 1% difference across the board.

For the dell 750W Platinum at ~400W usage i wouldn't mind paying the extra tho!
6% difference!
24W over a year does add up to 209kWh or around 25-28€ for me.
and it still uses a tiny inefficient high wattage fan oO;

chungenhung

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Quote from: allten on March 19, 2012, 10:16:40 AM

Still waiting for my single.
Get that delivered then lets talk.

For the rig box, I've been waiting to buy a 1/4 of one with another miner(s).
That's where I see it going for many.

this

WhitePhantom

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Quote from: jamesg on March 17, 2012, 04:51:59 PM

Quote from: DeathAndTaxes on March 17, 2012, 02:11:09 PM

Just make the "smaller" one and sell two to the people who ordered the "original rigbox".

I would be OK with this for my pervious orders of the rig box.

I would also be happy with two Mini-Rigs instead of the one Rig Box I ordered. Whatever BFL decides to do is fine with me.

allten

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You Don't Bitcoin 'till You Mint Coin

Still waiting for my single.
Get that delivered then lets talk.

For the rig box, I've been waiting to buy a 1/4 of one with another miner(s).
That's where I see it going for many.

Epoch

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Activity: 922

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Quote from: DeathAndTaxes on March 19, 2012, 09:42:08 AM

Quote from: rjk on March 19, 2012, 09:36:13 AM

Very good. But my reasoning wasn't reliability, it was efficiency. The curves on most if not all PSUs go all to shit when running under 25% or over 80%.

There isn't much difference for anything 80-Plus rated. For example Seasonic 1250W unit.

I hope I don't sound like a SeaSonic sale rep but here is my favorite mining rig PSU:
http://www.plugloadsolutions.com/psu_reports/SEA%20SONIC_SS-1250XM_ECOS%202811_1250W_Report.pdf

100% load - 88.7% efficiency
80% load - 89.8% efficiency
50% load - 91.4% efficiency
20% load - 89.8% efficiency

Excellent supply, and a good example of why load does not significantly affect efficiency with today's 80PLUS designs. My 'go to' supply is the OCZ Z850. Similar numbers to the 1250XM above (perhaps ~0.5% less across the board), but where the Seasonic costs $250; I can often get the Z850 for $100. The additional 50% capacity of the 1250XM is welcome (and sometimes necessary, depending on your requirements), but the extra $150 is reason to pause.

For mini-Rig purposes: 1250W is about as high as you can get for a 'household outlet' supply (1250/90% is about 1390W at the wall, which is near the continuous limit of 1440W), so if the mini-Rig will use something like this it would be fine.

rjk

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1ngldh

Quote from: BlackPrapor on March 19, 2012, 09:55:02 AM

You're right, but paying double price for a few more % is ridiculous at least (I'm talking about Platinum series PSU's)

I'll just leave this here: http://www.plugloadsolutions.com/psu_reports/DELL_D750E-S2_750W_SO-386_Report.pdf
The one and only Titanium rated PSU, at better than 96% efficiency. Can't find it for sale anywhere, but I wonder what it will cost in a few years when it gets removed from decommissioned servers.

BlackPrapor

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Quote from: rjk on March 19, 2012, 09:51:55 AM

Quote from: BlackPrapor on March 19, 2012, 09:46:45 AM

It's usually a couple percent less than the best it can do. And the best it can do is usually with around 70-80% load. If 2-3% efficiency is a lot for you, then you should buy Enermax Platimax PSU, and run it on 70% load - you should get around 94-95% efficiency.....for a hell of a lot of money, it will pay out when your grand children get their mortgage paid out.

This is true. However, that 2-3% efficiency shows up as reasonably substantial additional heat which a) can reduce the expected lifespan in the case of cheaper PSUs, and b) must be dealt with on the cooling side of things.

I tend to think in datacenter size proportions, so I consider efficiency carefully, factor in lifespan and ease of replacement, and sprinkle on some actual cost later. This will not usually apply to most users.

You're right, but paying double price for a few more % is ridiculous at least (I'm talking about Platinum series PSU's)

rjk

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Activity: 448

Merit: 250

1ngldh

Quote from: BlackPrapor on March 19, 2012, 09:46:45 AM

It's usually a couple percent less than the best it can do. And the best it can do is usually with around 70-80% load. If 2-3% efficiency is a lot for you, then you should buy Enermax Platimax PSU, and run it on 70% load - you should get around 94-95% efficiency.....for a hell of a lot of money, it will pay out when your grand children get their mortgage paid out.

This is true. However, that 2-3% efficiency shows up as reasonably substantial additional heat which a) can reduce the expected lifespan in the case of cheaper PSUs, and b) must be dealt with on the cooling side of things.

I tend to think in datacenter size proportions, so I consider efficiency carefully, factor in lifespan and ease of replacement, and sprinkle on some actual cost later. This will not usually apply to most users.

BlackPrapor

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Activity: 628

Merit: 504

Quote from: rjk on March 19, 2012, 09:36:13 AM

Quote from: DeathAndTaxes on March 19, 2012, 09:23:57 AM

Quote from: rjk on March 19, 2012, 09:10:57 AM

I think it will. Any builder knows that a PSU really shouldn't be running at more than 80% of full load continuously, which in this case is 80% of 1500 watts (1200 watts). Assuming they stick to this, power won't be a problem.

Says who? Rated power is rated power. "50% rule", "80% rule" are pure nonsense. People need to stop babying their power supply. Run it at full power. If it is solid (Seasonic) it will run for years at 100% load. If it is a piece of shit well then RMA it, and break it again, and RMA it, and break it again, and RMA it, and break it again and RMA it. Post of forums that it is a piece of shit, give it 1 egg on newegg, make a blog about how company xyz rips off customers.

Rated power is rated power. If a PSU can't put out more than 1000W CONTINUALLY then it should be rated at 1000W not 1200W. Consumers that baby the suppliers only subsidize substandard products.

I mean it would be like someone selling you a sports car which has a top speed of 160 mph but if you drive it faster than 80 mph it explodes and people say "dude everyone knows not to drive a sports car faster than 50% of rated speed). It is just as foolish to hold PSU to the same low standard.

Semi offtopic rant aside, the listed spec for RigBox is ~2500W so a 50% unit would likely be ~1250W.

Very good. But my reasoning wasn't reliability, it was efficiency. The curves on most if not all PSUs go all to shit when running under 25% or over 80%.

It's usually a couple percent less than the best it can do. And the best it can do is usually with around 70-80% load. If 2-3% efficiency is a lot for you, then you should buy Enermax Platimax PSU, and run it on 70% load - you should get around 94-95% efficiency.....for a hell of a lot of money, it will pay out when your grand children get their mortgage paid out.

DeathAndTaxes

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Gerald Davis

Quote from: rjk on March 19, 2012, 09:36:13 AM

Very good. But my reasoning wasn't reliability, it was efficiency. The curves on most if not all PSUs go all to shit when running under 25% or over 80%.

There isn't much difference for anything 80-Plus rated. For example Seasonic 1250W unit.

I hope I don't sound like a SeaSonic sale rep but here is my favorite mining rig PSU:
http://www.plugloadsolutions.com/psu_reports/SEA%20SONIC_SS-1250XM_ECOS%202811_1250W_Report.pdf

100% load - 88.7% efficiency
80% load - 89.8% efficiency
50% load - 91.4% efficiency
20% load - 89.8% efficiency

Also look at the "curve" it is almost a flat line compared to the bell curve shaped efficiency curves of a decade ago. 80-Plus may be imperfect and sometimes a lot of marketing but it has widened the "sweet spot" of PSU load curves.

IF SeaSonic says it is good for 1250W @ 120F well I am going to find out.

If it can't do that they shouldn't say it. Given they have 5 year warranty they have a lot more to lose than me by over promising.

That being said loading to 80% isn't "bad". It gives you a little headroom as the PSU ages. It is a lot better than the "50% rule" nonsense which was common around here even just a year ago.

Topic: Mini-Rig from Butterflylabs - page 10. (Read 21155 times)