at what point is a person considered a "respectable" miner? - page 3.

JWU42

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Quote from: DeathAndTaxes on February 09, 2012, 12:48:30 PM

Quote from: JWU42 on February 09, 2012, 12:39:55 PM

Quote from: DeathAndTaxes on February 09, 2012, 12:08:39 PM

Quote from: JWU42 on February 09, 2012, 11:36:51 AM

He used 12/3 as I recall...

I deleted my post above because it likely contains misinformation based on comment from a friend who is electrician.

While 12 gauge wiring is good for 30A Section 240.4(D) limits branch circuits to 15A on 14 gauge, 20A on 12 gauge, 30A on 10 gauge.

Still you could switch to 240V 20A at some point in the future giving you 80%*20*240V = 3.8KW per drop.

Thanks D&T...

Then I would need to get "The Clamp" to measure wattage as the Killa-aWatt is worthless on 240V?

Correct. Alternatively there are 240V devices which are similar to Kill-a-Watt.

http://cablesaurus.com/index.php?route=product/product&path=15&product_id=30

Cablesaurus sells one. I have no idea how good it is.

A good clampmeter that kind measure AC current accurately (often called "True RMS") is kinda expensive, >$140 ish. DC only or AC/DC averaging meters are cheaper but aren't going to do you any good for measuring AC efficiency.

So a good cheap kill-a-watt like meter for 240V it would be useful.

Good news for me is the miners are in the basement in the same room as the box (i.e., not much to run). Might have him put in the 240v 30A right beneath the box and then i have the 12 foot cord from the PDU to my advantage...

eviltt

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Quote from: Inspector 2211 on February 09, 2012, 01:18:57 PM

Quote from: eviltt on February 08, 2012, 08:02:59 PM

like what gh level?

Like i am putting my first dedicated rig together.. aiming for 2.4gh..

need a bit more funding to put get more 5970s

You are a respectable miner if you have already tripped circuit breakers and/or contributed to global warming and/or got kicked out of your "mining office" by your commercial landlord.

The latter happened to me half a year ago.
3 day notice to vacate for breach of lease terms.
"The owner has seen the electrical bill of the entire office building DOUBLE, and he wants you out."
"Consider this your 3 day notice."

I had four mining rigs plugged into the 20 amp circuit of the left wall, and four mining rigs plugged into the 20 amp circuit of the right wall, drawing close to 40 amps total. Once I tried to print a document on the laser printer - when the laser printer heated up its toner filament, it caused the circuit breaker to trip.

Good times. Grin

hahaha.. i thought of doing that renting some space at an executive office building.. only concern i have is that they tend to turn the AC off on the weekends Sad

DeathAndTaxes

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Gerald Davis

Quote from: rjk on February 09, 2012, 01:03:50 PM

The reasons for choosing 277VAC are:
a) Still only one phase to worry about - not two or three per PSU. Less wiring.
b) No 480 --> 240 VAC transformer losses. (Not sure how much efficiency loss there is, but I don't think the transformer could be any higher than 96-97% efficient. Mine is a 45Kva SquareD)
c) Smaller gauge wiring due to the higher voltage.

Well "a" doesn't really matter. If you home isn't 3 phase you aren't getting 3 phase anyways.

On "b" I think you are forgetting about the 480 -> 277 VAC transformer. Wink

Still transformers tend to be very efficient. 97%+ is certainly likely, 99%+ is possible. Energy in = Energy out. So all the energy on the 480 VAC side becomes 240 VAC or heat. An inefficient transformer on a mains where it could be pulling 100 amps+ would quickly melt. Some quick numbers. The transformer is rated at 45KVA so at 5% inefficiency and peak load ~2.5KW would be converted into heat. Heat output on the transformer would be more than 10x 5970s.

Optimally the best thing for you would be a high efficiency 5KW 480VAC to 12VDC powersupply. You could power an entire rack of GPUs.

Then just run the low wattage mixed voltage components off some low wattage ATX PSU units. Now if you found and rigged that you might be a serious miner.

Inspector 2211

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Quote from: eviltt on February 08, 2012, 08:02:59 PM

like what gh level?

Like i am putting my first dedicated rig together.. aiming for 2.4gh..

need a bit more funding to put get more 5970s

You are a respectable miner if you have already tripped circuit breakers and/or contributed to global warming and/or got kicked out of your "mining office" by your commercial landlord.

The latter happened to me half a year ago.
3 day notice to vacate for breach of lease terms.
"The owner has seen the electrical bill of the entire office building DOUBLE, and he wants you out."
"Consider this your 3 day notice."

I had four mining rigs plugged into the 20 amp circuit of the left wall, and four mining rigs plugged into the 20 amp circuit of the right wall, drawing close to 40 amps total. Once I tried to print a document on the laser printer - when the laser printer heated up its toner filament, it caused the circuit breaker to trip.

Good times. Grin

rjk

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Activity: 448

Merit: 250

1ngldh

Quote from: DeathAndTaxes on February 09, 2012, 12:33:55 PM

Quote from: rjk on February 09, 2012, 12:14:48 PM

I saw somewhere that Facebook is using 277v PSUs to save even more energy somehow. Does anyone know where to get these PSUs, and how high of wattage they are available in? I have 480 3phase that works out to 277 phase-to-ground, and if its more efficient I should be using it.

Right now my 240v comes thru a transformer that does 480 --> 240 conversion, at who knows what efficiency. Skipping that would help even more.

277V PSU won't do you any good if your mains are 480V to 240V. I would imagine no transformer is involved you are simply supplied 2x 240V legs.

Given there are now 80-Plus Platinum PSU getting 93%+ efficiency at 75% load (and likely +2% higher @ 240V) there isn't much inefficiency left to trip away.

Google also had custom PSU built for their datacenter years ago but that was back when avg ATX PSU was 70% efficient.

I have access to a panel on both sides of the transformer. I found the PSU I was looking for: http://opencompute.org/projects/power-supply/
It actually is autoranging from 180v to 305v, but optimal efficiency is at 277. According to the spec sheet, numbers are as follows:

>0.95 power factor and <10% THD with harmonics up to and including 40, at 277VAC RMS 50 or 60 HZ.
90% efficiency at 20% load, 95% at 50% load, and 91% at 100% load.

However the PSU is only 450 watts. The reasons for choosing 277VAC are:
a) Still only one phase to worry about - not two or three per PSU. Less wiring.
b) No 480 --> 240 VAC transformer losses. (Not sure how much efficiency loss there is, but I don't think the transformer could be any higher than 96-97% efficient. Mine is a 45Kva SquareD)
c) Smaller gauge wiring due to the higher voltage.

So it makes sense for datacenters with thousands of custom servers like FB and Google, but probably not much for the average miner.

Kluge

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Quote from: rjk on February 09, 2012, 11:08:26 AM

Quote from: JWU42 on February 09, 2012, 11:06:27 AM

I am wondering if it would have been better to do the 240V 30A thing -- didn't know any better at the time.

I had our electrician put in 4 20amp circuits (120V) two weeks ago.

Higher voltage gives you slightly better efficiency. I'm just about to switch, so I should get a good clamp meter so I can determine the change in the power usage.

If anyone's interested in some graphs.....

https://docs.google.com/viewer?a=v&q=cache:ukzeb9vRpNwJ:pqlit.eaton.com/ll_download_bylitcode.asp%3Fdoc_id%3D11366+&hl=en&gl=us&pid=bl&srcid=ADGEESje68l6FOYZ8zwk-4FqJnO9Dqf-9cDrP4StWMi1X7JJSuZtHEOjN6bTK8KoyjDgg8I1Rgy33ttjV8vvDDy9vtD2y-hIoeteutnkW-G9baV3q7VTtwY_hMOuIDvBJDKTKAnIgrQ7&sig=AHIEtbQNixyUn7sxvcECcb0bI4Z_6ZHJsg

Though it'd depend on the PSU, high-end PSU gains seem to be ~2-3%.

I spend ~$70.50/month (@~$.12/kWh) to power 6 5850s running on three rigs @~2GH/s. Assuming 2% efficiency gain, power savings per month would be ~$1.41/month. *12=$16.92/year - (Assuming a 3% efficiency gain, $25.38/year). Not sure this would be worth the time, space, and up-front cost unless you're running many rigs (or have electric appliances which'll run on 240v).

DeathAndTaxes

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Gerald Davis

Quote from: JWU42 on February 09, 2012, 12:39:55 PM

Quote from: DeathAndTaxes on February 09, 2012, 12:08:39 PM

Quote from: JWU42 on February 09, 2012, 11:36:51 AM

He used 12/3 as I recall...

I deleted my post above because it likely contains misinformation based on comment from a friend who is electrician.

While 12 gauge wiring is good for 30A Section 240.4(D) limits branch circuits to 15A on 14 gauge, 20A on 12 gauge, 30A on 10 gauge.

Still you could switch to 240V 20A at some point in the future giving you 80%*20*240V = 3.8KW per drop.

Thanks D&T...

Then I would need to get "The Clamp" to measure wattage as the Killa-aWatt is worthless on 240V?

Correct. Alternatively there are 240V devices which are similar to Kill-a-Watt.

http://cablesaurus.com/index.php?route=product/product&path=15&product_id=30

Cablesaurus sells one. I have no idea how good it is.

A good clampmeter that kind measure AC current accurately (often called "True RMS") is kinda expensive, >$140 ish. DC only or AC/DC averaging meters are cheaper but aren't going to do you any good for measuring AC efficiency.

So a good cheap kill-a-watt like meter for 240V it would be useful.

JWU42

legendary

Activity: 1666

Merit: 1000

Quote from: DeathAndTaxes on February 09, 2012, 12:08:39 PM

Quote from: JWU42 on February 09, 2012, 11:36:51 AM

He used 12/3 as I recall...

I deleted my post above because it likely contains misinformation based on comment from a friend who is electrician.

While 12 gauge wiring is good for 30A Section 240.4(D) limits branch circuits to 15A on 14 gauge, 20A on 12 gauge, 30A on 10 gauge.

Still you could switch to 240V 20A at some point in the future giving you 80%*20*240V = 3.8KW per drop.

Thanks D&T...

Then I would need to get "The Clamp" to measure wattage as the Killa-aWatt is worthless on 240V?

JWU42

legendary

Activity: 1666

Merit: 1000

Quote from: rjk on February 09, 2012, 11:39:11 AM

Quote from: JWU42 on February 09, 2012, 11:36:51 AM

He used 12/3 as I recall...

12/2 with ground, or 12/3 with ground?

Now you are getting outside my knowledge base. I thought I was doing well with knowing the whole 12/3 part Wink

DeathAndTaxes

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Activity: 1218

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Gerald Davis

Quote from: rjk on February 09, 2012, 12:14:48 PM

I saw somewhere that Facebook is using 277v PSUs to save even more energy somehow. Does anyone know where to get these PSUs, and how high of wattage they are available in? I have 480 3phase that works out to 277 phase-to-ground, and if its more efficient I should be using it.

Right now my 240v comes thru a transformer that does 480 --> 240 conversion, at who knows what efficiency. Skipping that would help even more.

277V PSU won't do you any good if your mains are 480V to 240V. I would imagine no transformer is involved you are simply supplied 2x 240V legs.

Given there are now 80-Plus Platinum PSU getting 93%+ efficiency at 75% load (and likely +2% higher @ 240V) there isn't much inefficiency left to trip away.

Google also had custom PSU built for their datacenter years ago but that was back when avg ATX PSU was 70% efficient.

rjk

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Activity: 448

Merit: 250

1ngldh

I saw somewhere that Facebook is using 277v PSUs to save even more energy somehow. Does anyone know where to get these PSUs, and how high of wattage they are available in? I have 480 3phase that works out to 277 phase-to-ground, and if its more efficient I should be using it.

Right now my 240v comes thru a transformer that does 480 --> 240 conversion, at who knows what efficiency. Skipping that would help even more.

DeathAndTaxes

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Gerald Davis

Quote from: JWU42 on February 09, 2012, 11:36:51 AM

He used 12/3 as I recall...

I deleted my post above because it likely contains misinformation based on comment from a friend who is electrician.

While 12 gauge wiring is good for 30A Section 240.4(D) limits branch circuits to 15A on 14 gauge, 20A on 12 gauge, 30A on 10 gauge.

Still you could switch to 240V 20A at some point in the future giving you 80%*20*240V = 3.8KW per drop.

Joshwaa

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I am currently installing another 2 40 amp drops from my main panel.
Might need another A/C unit too. Sad

I need 1.21 Gigawatts!!! Oh and my computer to go 88mph! lol

rjk

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Activity: 448

Merit: 250

1ngldh

Quote from: JWU42 on February 09, 2012, 11:36:51 AM

He used 12/3 as I recall...

12/2 with ground, or 12/3 with ground?

JWU42

legendary

Activity: 1666

Merit: 1000

He used 12/3 as I recall...

JWU42

legendary

Activity: 1666

Merit: 1000

OK - help out those of us less electrically inclined Wink

4 x 20A @ 120V = 80A * 80% = 64A @120 = 7,680 W

Now that is 1,920W per outlet or 960W per "plug". Not quite enough for a 4x7970 rig or a 3x5970 + 2x5870 as the latter will pull close to 1200W. This leaves one "plug" kinda worthless = BAD.

1 x 30A @ 240V = 30A * 80% = 24A @ 240 = 5,760 W

Then you need a PDU which can be had for ~$60. These have tons of plugs but still need to balance the circuits...

Just thinking out loud here...

rjk

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1ngldh

Quote from: JWU42 on February 09, 2012, 11:06:27 AM

I am wondering if it would have been better to do the 240V 30A thing -- didn't know any better at the time.

I had our electrician put in 4 20amp circuits (120V) two weeks ago.

Higher voltage gives you slightly better efficiency. I'm just about to switch, so I should get a good clamp meter so I can determine the change in the power usage.

JWU42

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Activity: 1666

Merit: 1000

I am wondering if it would have been better to do the 240V 30A thing -- didn't know any better at the time.

I had our electrician put in 4 20amp circuits (120V) two weeks ago.

Brunic

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Quote from: Starlightbreaker on February 09, 2012, 03:28:38 AM

you're missing another one.

if you can produce extra heat and sell it to your neighbors cheaper than the oil company.

...wait, i think that's more like "overkill" than "respectable"

You're giving me ideas.... Grin

Starlightbreaker

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Quote from: Brunic on February 09, 2012, 02:31:25 AM

Consider I'm living in a country where -20 is common in January.

-If you can heat your feets with your mining rig, you're just starting.
-If you can heat a room with your mining rig, you have a nice hobby.
-If you're starting to save on heating because you heat the house, you're serious dude.
-If you can heat a whole 4-story house, with people keeping the windows open because it's too hot, and having the oil company giving you refunds on your heating bill, I believe it is the point where you are "respectable".

you're missing another one.

if you can produce extra heat and sell it to your neighbors cheaper than the oil company.

...wait, i think that's more like "overkill" than "respectable"

Topic: at what point is a person considered a "respectable" miner? - page 3. (Read 8487 times)