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Bitcoin Difficulty: 35,002,482,026
Estimated Next Difficulty: 35,374,044,839 (+1.06%)
Adjust time: After 250 Blocks, About 1.7 days
Hashrate(?): 243,539,654 GH/s
Block Generation Time(?):
1 block: 9.9 minutes
3 blocks: 29.9 minutes
6 blocks: 59.7 minutes
Updated: 15:8 (4.3 minutes ago)
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Actually given the same load attached to a cable, the longer the cable, the more the resistance, the greater the voltage drop across the cable (lost as heat), but the current drops. Since current drops, an infinitely long cable would have all the voltage drop but no current and would be cool.
No, current doesn't drop unless you're hooked up to a resistor. A power supply is (close to) a constant power device, so current will increase in proportion to the voltage drop. It will be pretty minor though. Cable heating won't really change, since while you'll have 3.3x the voltage drop with a 10ft vs 3ft cable and essentially the same current and will therefore dissipate 3.3x more power, the cable also has 3.3x more surface area to dissipate heat. That's why wire gauges are rated for a certain current without regard for length. You're wrong! Current will drop regardless of load if cable is long enough. The wire itself becomes a big resistor. Even if the supply was ideal, there would be little current getting to the load (or going through the cable) if the cable was long enough. Cable resistance approaches infinity as length increases. Of course, the difference between 3 to 10 feet is insignificant. No, I am not. Current will rise as cable length rises and voltage at the load will decrease until either the input current or input voltage protection of the PSU trips at which point the PSU will shut down and current will go to (almost) 0. For an S4 pulling 1400W (with a PF=1) from a 240V line and assuming the PSU trips off at 100V, you'd be pulling 14A and could thus use up to a 600m long 14 gauge cable. IE, preposterously long. All i know is i had a heavy gauge 10ft cable on 3 avalons and the ends were getting reallllly hot. Changed over to a heavy gauge 3ft cable and no problems. JT When you said you changed over "...to a HEAVY GAUGE 3ft cable and no problems," I'm simply saying the "HEAVY GAUGE" [switching from 18 AWG or 16 AWG to 14 AWG] was what cut down the heat RATHER THAN THE LENGTH of the power cord. Also, I'm not shouting when using caps. The caps are only for EMPHASIS. |
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No, current doesn't drop unless you're hooked up to a resistor. A power supply is (close to) a constant power device, so current will increase in proportion to the voltage drop. It will be pretty minor though.
The sole job of resistance is to oppose current [DC or AC]. Also, resistance will not drop (consume; eat) any voltage unless current is flowing through it. Being that AC will flow ON or THROUGH a capacitor no matter if the capacitor is open (normal) or shorted (abnormal); voltage is dropped by the resistance in the metal plates of the capacitor (line cord). However, I will not continue in the "science" of electrons flowing on/through a capacitor. I will simply provide a table below for current ratings in wire other than magnet wire. Current Ratings:Most current ratings for wires (except magnet wires) are based on permissible voltage drop, not temperature rise. For example, 0.5 mm^2 wire is rated at 3A in some applications but will carry over 8 A in free air without overheating. You will find tables of permitted maximum current in national electrical codes, but these are based on voltage drop (not the heating which is no problem in the current rating those codes give). Which I say again, "the wire gauge (AWG) used is more important than the length [when looking at power cords for peripherals]. Here is a small current and AWG table taken from the Amateur Radio Relay Handbook, 1985. AWG dia mils circ mils open air A cable Amp ft/lb bare ohms/1000' 10 101.9 10380 55 33 31.82 1.018 12 80.8 6530 41 23 50.59 1.619 14 64.1 4107 32 17 80.44 2.575 Mils are .001". "open air A" is a continuous rating for a single conductor with insulation in open air. "cable amp" is for in multiple conductor cables. Disregard the amperage ratings for household use. To calculate voltage drop, plug in the values: V = DIR/1000 Where I is the amperage, R is from the ohms/1000' column above, and D is the total distance the current travels ( don't forget to add the length of the neutral and hot together - ie: usually double cable length). Design rules in the CEC call for a maximum voltage drop of 6% (7V on 120V circuit).What I'm arguing: is the AMOUNT of the resistance in a 14 AWG power line cord at 12 feet in length will not get as hot as a 16 AWG power line cord of the same length in a circuit running at 11.666667 AMPS (Bitmain Antminer S4 @ 1400 watts = 11.666667 AMPS). This is THE SAME THING you pointed out in your statement I quoted below. WE AGREE!!! GAUGE (AWG) IS MORE IMPORTANT THAN LENGTH; since the length we are talking about is really not very long at all. Cable heating won't really change, since while you'll have 3.3x the voltage drop with a 10ft vs 3ft cable and essentially the same current and will therefore dissipate 3.3x more power, the cable also has 3.3x more surface area to dissipate heat. That's why wire gauges are rated for a certain current without regard for length.
MY SENTIMENTS EXACTLY |
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Here's what pisses me off:
Bitmain says the following regarding their S4, "Power line not included. You may look for one line with no less than 16A in your local market."
Well, I've searched the WORLD WIDE WEB for a C14 Power cord and cannot find one rated higher than 15 amps.
WTF?
Pretty sure they made a typo and meant 16Awg. If you're running on 240v you need an 18AWG cord, ND if you're running 120v use a 14AWG cord. I bought this one: Amazon.com: Tripp Lite Heavy Duty Power Cord, 16A,14AWG (NEMA 5-15P to IEC-320-C15) 8-ft.(P019-008): Electronics http://www.amazon.com/gp/product/B0091F8GP6/#It's a replacement for a heavy duty server room style UPS. When i got it, the packing slip said 16A but the packaging the cord was in said 15A. Anyway until I received that my S4 ran fine for 2 days with a standard el-cheap-o 10A PC power cord that I had laying around in a box in my closet, so I wouldn't stress about it. I have seen the one you purchased on Amazon. It is a kettle cord. A C-15 made to fit a C-16 connector. It is used for higher amperage appliances. It also has a valley in the C16 connect which does not allow a C-13 cord to plug into it. However, a C-15 or C1-3 cord can plug into a C-14 connect. The S4 has a C-14 connect. I'm just going to purchase Trip-Lite 14 AWG C13 10 feet cord for the S4. Uses the same gauge wire as the Trip-Lite C-15 8 feet cord you purchased from Amazon. Thanks for your description. David Something else yall need to remember is the length of the cord. A 10 ft cord will get hotter and pull more amps than a 3 foot cord. All my miner power cables are 3 ft or less with an iso bar behind them. JT There isn't that much more resistance in a 10 feet cord versus a 3 foot cord; even if we were talking about mili-amps. Since we are talking about "amps" and not "mili-amps," the amount of resistance in a 10 feet cord versus a 3 feet cord is irrelevant. Even if we were talking about mili-amps, the amount of resistance in 10 feet of 14 AWG cable versus 3 feet of 14 AWG cable isn't much difference to amount to anything. Wire Gauge Resistance per foot4 .000292 6 .000465 8 .000739 10 .00118 12 .00187 14 .0029716 .00473 18 .00751 20 .0119 22 .0190 24 .0302 26 .0480 28 .0764 3 Feet of 14 gauge (AWG) [.00297 x 3] = .00891 Ohms 10 Feet of 14 gauge (AWG) [.00297 x 10] = .02970 Ohms The gauge would be more important than the length in this particular case. That is my opinion. This is why I would rather have 14 AWG C-13 Cord rather than 16 AWG (Average Wire Gauge) C-13 Cord. |
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Here's what pisses me off:
Bitmain says the following regarding their S4, "Power line not included. You may look for one line with no less than 16A in your local market."
Well, I've searched the WORLD WIDE WEB for a C14 Power cord and cannot find one rated higher than 15 amps.
WTF?
Pretty sure they made a typo and meant 16Awg. If you're running on 240v you need an 18AWG cord, ND if you're running 120v use a 14AWG cord. I bought this one: Amazon.com: Tripp Lite Heavy Duty Power Cord, 16A,14AWG (NEMA 5-15P to IEC-320-C15) 8-ft.(P019-008): Electronics http://www.amazon.com/gp/product/B0091F8GP6/#It's a replacement for a heavy duty server room style UPS. When i got it, the packing slip said 16A but the packaging the cord was in said 15A. Anyway until I received that my S4 ran fine for 2 days with a standard el-cheap-o 10A PC power cord that I had laying around in a box in my closet, so I wouldn't stress about it. I have seen the one you purchased on Amazon. It is a kettle cord. A C-15 made to fit a C-16 connector. It is used for higher amperage appliances. It also has a valley in the C16 connect which does not allow a C-13 cord to plug into it. However, a C-15 or C1-3 cord can plug into a C-14 connect. The S4 has a C-14 connect. I'm just going to purchase Trip-Lite 14 AWG C13 10 feet cord for the S4. Uses the same gauge wire as the Trip-Lite C-15 8 feet cord you purchased from Amazon. Thanks for your description. David |
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Here's what pisses me off:
Bitmain says the following regarding their S4, "Power line not included. You may look for one line with no less than 16A in your local market."
Well, I've searched the WORLD WIDE WEB for a C14 Power cord and cannot find one rated higher than 15 amps.
WTF?
Pretty sure they made a typo and meant 16Awg. If you're running on 240v you need an 18AWG cord, ND if you're running 120v use a 14AWG cord. 240V/16A plugs are common in other countries. The cable that shipped with my S2 was a 16A 240V 50Hz. Your S2 will be fine with a 15A cable. The more I thought about it, 1400 watts [S4 built in PSU] amounts to no more than 11.6666667 AMPS. So, a 15 AMP should be fine. I'm still getting a 14 AWG rather than 16 or 18 AWG. |
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well 2 close to flat diff jumps looks fantastic adds another two weeks to the life of some miners  Certainly does. I think many miners are still safe at for a little while. For some reason the hash rate gets high over the weekend then gets back lower after the weekend. I don't know why? If I had miners, I would keep them on 24/7 as long as I could. well some companies hash on equipment they are supposed to ship you know well we cant ship sat or sun so lets point em at our pool etc Interesting theory. |
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well 2 close to flat diff jumps looks fantastic adds another two weeks to the life of some miners Certainly does. I think many miners are still safe at for a little while. For some reason the hash rate gets high over the weekend then gets back lower after the weekend. I don't know why? If I had miners, I would keep them on 24/7 as long as I could. |
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Bitcoin Difficulty: 35,002,482,026
Estimated Next Difficulty: 35,298,274,848 (+0.85%)
Adjust time: After 342 Blocks, About 2.4 days
Hashrate(?): 251,876,881 GH/s
Block Generation Time(?):
1 block: 9.9 minutes
3 blocks: 29.9 minutes
6 blocks: 59.7 minutes
Updated: 23:12 (4.7 minutes ago)
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Yes you are correct. I was just thinking about how things have changed so quickly. ie. a 5gh/s tolerance was a big deal.
So, it was a "5 gh/s" shy of 2,000 GH/s or was it 200 GH/s shy ["1.8 TH/s average," like in your first statement.] shy of the 2 TH/s guarantee? The reason I'm curious is because I'm about to purchase my first S4 in a couple more days. I've almost mined the BTC needed to purchase it from Bitmaintech.com. I'm just saying, I would be disappointed if it's not hashing the 2000 GH/s guaranteed. I would need to send my S4 back if it was 200 GH/s shy of the 2000 GH/s guaranteed. If it was just 5 GH/s shy of the 2000 GH/s, I could probably live with that; but not 200 GH/s shy of the guarantee. no this was a pool issue. my underclocked s-3 runs at 400-410gh. the last two hours it has dropped out and back and is a mess. but most of the time I get my 400-410gh here . my s-3 is clocked to freq 200 so 400-410 is normal. gotcha! Thanks for clarifying!!! I was beginning to get very concerned. |
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Yes you are correct. I was just thinking about how things have changed so quickly. ie. a 5gh/s tolerance was a big deal.
So, it was a "5 gh/s" shy of 2,000 GH/s or was it 200 GH/s shy ["1.8 TH/s average," like in your first statement.] shy of the 2 TH/s guarantee? The reason I'm curious is because I'm about to purchase my first S4 in a couple more days. I've almost mined the BTC needed to purchase it from Bitmaintech.com. I'm just saying, I would be disappointed if it's not hashing the 2000 GH/s guaranteed. I would need to send my S4 back if it was 200 GH/s shy of the 2000 GH/s guaranteed. If it was just 5 GH/s shy of the 2000 GH/s, I could probably live with that; but not 200 GH/s shy of the guarantee. |
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k. Thanks for checking. It's probably this instance of bfgminer I'm running  I see what you did there. Now that's funny right there  Updated the S4 with your release today and pointed it at the solo pool. I'm seeing an average of about 1.8t with it. Does that sound about right? Isn't it amazing we are up to a point where 200gh/s can be within 10% tolerance? Specifications: * Chip Operating Voltage: 0.72V * Chip Quantity per unit: 160 * Hash Rate: 2,000GH/s guaranteed * Power Efficiency: 0.69Watt/GH/s at the wall * Over clocking: About 10%, but not guaranteed * 3U Rack 432mm*442mm*133mm * PSU inside: 1400W, 80PLUS gold, C14 input socket. Power line not included. You may look for one line with no less than 16A in your local market * Temperature: 40-50 degree Celsius tested in the mining farm * Fan Speed: 3900RPM * Stable but a little bit noisy * Ethernet connection, Stand alone * Certificate Compliance: FCC/CE I don't understand... The 10% tolerance regards "Over Clocking," which is "...not guaranteed."However, a "Hash Rate: 2,000 GH/s (2 TH/s) is guaranteed." |
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Damn, just noticed 2nd block I (32955) have found at slush since 02/14. Both ones have been found by my S2's who would have thunk? Only need 32 more to make the list. sweeeeeeeeet thumbs up! |
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It will be a nice surprise if we find our next one within 15 hours.
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^ it's definitely appreciated You're all very welcome. |
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Bitcoin Difficulty: 35,002,482,026
Estimated Next Difficulty: 35,462,875,526 (+1.32%)
Adjust time: After 383 Blocks, About 2.6 days
Hashrate(?): 255,019,524 GH/s
Block Generation Time(?):
1 block: 9.9 minutes
3 blocks: 29.7 minutes
6 blocks: 59.4 minutes
Updated: 15:35 (1.2 minutes ago)
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What's the diff in price?
Edit: Make sure you check desables. Most miners other than bitmain are LOUD. I have two Rockminer RK-Boxes that sound as loud as a big vaccum machine.
these are loud hence why i got the wifi so i can set in my garage in an area i dont have cable ran for the 20 dollar mod it was worth not having to break out a drill etc lmao the fan puts out crazy cfm and pressure link below https://www.youtube.com/watch?v=Wqc72EOuteUDAMN, that is LOUD LOL |
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I understand as I was really wanting to stay with a all in one like s3's and my cointerra however i was able to sell my cointerra and one s3 on ebay to buy 1 prisma with rpi and image and wifi and had the btc i mined last month from those 2 to get the other i will hash 1th/s faster and use 1000w less power so for me it was an easy decision the gui that crazy has running on the connected pi makes it pretty straight forward 8 pool failover etc is nice and since wifi wont be as affected with network issues by using same usb port for network traffic and connecting the prisma's the S4 was just as much an investment as PSU's if I needed as I would need to make some electrical changes Etc buying appropriate power cords and having outlets rated to handle the load so for me personally 1100 dollars for 2.8th/s was the better route even having to buy psu i could of gotten 4 650w for prob 100-200 max Understand, makes sense. My miners will be staying in a coat closet downstairs adjacent to the garage. Looking forward to showing y'all pics when I'm done with it. I think I've pretty much made up my mind on the S4's. Especially, since they fixed the PSU issue and Slush allows diff setting now. I also like purchasing from the manufacturer with a good warranty. Not doubting the Prisma has a good warranty. I'm sure they probably do. Going with the S4 now for more familiarity. |
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