If you try and mine it all on one breaker you will most certainly trip it (most 120v breakers are 15-20A)...4X L3+ miners will pull 27 amps on 120v. Even two on a single breaker is pushing 120v. So good luck finding 4 separate outlets that are on separate breakers.

Its really easy to make a 240v box. Even if your not an electrician its not rocket science. Just buy a double pole 30A breaker (about 10 bucks), some 10gauge wiring (its orange color in any home supply store), and some outlets. Take off your panel and turn off the main breaker if you've never done this to be super safe. The breaker literally just plugs into the main bus slots inside your panel. Connect the black and white wires to the breaker, and the exposed copper to the ground bus bar. Then just hook up the other end to your outlets (you can use the 120v kind, almost all PSUs work at 240v so there is no need to buy 240v outlets and new cables for PSU etc).

You can pull at total of about 6kw from this 30A double pole breaker...enough to power all 4 of your L3+ and then some! Plus all your wires will be super cool and don't have to worry about your old 120v wiring in your house catching fire.

Doge has double in price (the main merged mine coin with Litecoin). Thats the only reason PPS went up to 108. FYI for each LTC block they find, they mine an equivalent of ~2.7 of LTC worth in Doge...thats an equivalent of ~111% PPS so effective pool fee is 2-3%

Yea variance is insane now for even 1GH worth of miners. 2 of mine have been mining for almost 2 weeks without a single block. Would have been screwed if I tried to solo.

Yea this should be interesting to watch...this is why I only buy hardware that is already ROIed (i.e. I only buy with pure profit). This kind of probability is nice for the short term, but its definitely not sustainable.

Yup, if your still dealing with 120v for mining your going to burn something down eventually (especially if the outlet is not near your panel).

This is what all my miners run off...DIY 240v junction boxes running 10AWG to 30A double pole breakers in panel (capable of at least 6kw continous draw per box). Each box has relays controlled by wireless pi's, so always have full remote control shutoff/start up for locked hardware etc.

Dont need to step foot in mine unless im adding new stuff

How bout that for an equivalent of a 1K USD PDU unit for 50 bucks worth of parts 

Yea sorry I was compare it to the S5 boards. I don't have any S7s or 9s. It is controllable, the reg is connected via a PIC, but you have to hack their driver. Its not currently exposed user side.

These wont be viable for mining...Your probably looking in the 1K+ range per card with HBM2 16GB stack...and eth mining in the 40-60 MH range. You can buy 5-6 570s for the price of one of these.

The board is designed in an array of 12 serialized banks of 6 chips. So each bank of 6 chips receives whatever the input voltage is divided by 12. Their first serialized power boards just divided the input voltage straight from the power supply. So whatever was coming in those 12v inputs to the boards is what the chips received (i.e. if the input voltage was really 11.5 chips would receive 958mv at the core, or if it was 12.5 they would receive 1042mv. This was a wide range for different power supplies etc which caused too high of core voltage and thats why so many S5 boards got fried.

This board has a single regulator that regulates that 12v input, (whatever it is) to a set point (I haven't measured it yet but I'm assuming its going to be in the 9-11v range for these chips, which translates to a core voltage of around 800-900mv).

So the cool part about this setup is that first you can use a wide range of input voltages (controller is LM27402 with input range of 3-20v), second the core voltage on the serial chain can be under/over volted, and third you have a clean supply to the chips and don't have to worry about PSU spikes/sags on input voltage.

Well I'm speaking from a purely engineering standpoint, and compared to the last thing I bought (used) from bitmain being an S5 they have pretty much perfected these miners. Also the last scrypt machines Ive used were Zeus/Alcheminers (which were crap, and almost all 500 units of alcheminers sold are running my firmware these days which fixed alot of issues with them).

I know you bought in early with the L3, which seemed like were the guinea pig test bed for their L3+'s, but I really cannot find anything wrong with the L3+ from a technical perspective. The thermal engineering alone is impressive...these things have chip densities rivaled by immersion boards(more on that in a bit), on air cooling. The serial design is also pretty rock solid. At the top there is a voltage regulator that actually regulates the input voltages divided by the serial chain (which their previous machines did not do and was one of the reasons for fried boards). The actual regulator has an inductor rated for 40 amps, plus dual high side mosfets rated for 60 AMPS continuous EACH. For comparison the typical power draw of each board at stock settings is about 15-16 amps. Thats WAY overbuilt by cheap miner engineering standards.

So back to immersion, my guess is that Bitmain is running these boards for their hashnest cloud in immersion coolers, and probably have them running at near the maximum capacity of the regulator (which is 30-40 amps). I would not be surprised if they have them hashing in the 800mh range. I might break out my immersion prototype tank for these and see what I can do

https://www.youtube.com/watch?v=p5-BaH8_SAk

So after tearing these things apart and figuring out how they work (driver for these are open source as well which is cool), pretty sure that bitmain is purposely shipping these to underperform. The actual boards are built to output way more power than they currently are with shipped settings.

I've been able to play with the voltage controller on the boards and have them hashing at over 600mh currently with same power draw lol. I might try a over volt/ over clock and see what I can push them at within the thermal envelope.

Sure thing...GPU3 is the 570 pulse card, been running like this for days had to restart the other day so thats why its "only" at 22 hours stable.

Just buy a dual pole breaker...connected some 12 gauge wire to it, stick the breaker in your panel and connect a socket box on the other end. Wallah 240v socket for $20 worth of parts and half an hour of your time.

Its really not as hard or intimidating as it seems, just double check your wiring and don't switch on the breaker before everything is wired and you'll be set.

Doing 30MH on the RX 570 Pulse with -200mv (775mv core voltage). Pulling 95 watts at the wall

Was it on stock clocks or were they overclocked?

The firmware is supposed to have auto-shutdown if any of the boards get hotter than 80c, so I doubt it was an overheat issue. Either a FET blew on the input rail on one of the boards, or one of the chips in the chain blew.

They already own it 1 month after selling the L3+. All the chinese pools which are more or less controlled/under the influence of bitmain account for 80+% of the hashrate currently.

Of course I had to take one apart and see how it works

Hashboards simply slide in on rails inside aluminum enclosure and are just secured by the top fan mount



Top of hash board with individual heatsinks glued on each of the 72 chips. Inductor and input/output caps are on the top



Back of hashboard...so this is obviously a serial design, there are 12 banks of 6 chips. Each bank is connected in series with eachother, so core voltage is around input voltage/12 (probably around 1v). What interesting is that there is what seems to be a controllable voltage regulator on the input (since each board pulls 16 amps you can easily regulate the input voltage for the whole series design with just a single regulator). Their past designs just straight up divided the input voltage from the supply (which is why you could easily fry those boards with PSUs that output higher than 12v).



And a shot of their custom manufactured beaglebone and breakout board for it.




Should be able to get some interesting overclocks/undervolts once I get in the beaglebone and figure out how to access the voltage controller (hopefully its not fixed).

Even though I hate these guys and how they act, they sure know how to make solid miners. Just set up one and initial impressions are pretty good. They are dead on for the specs.

Each hashboard is currently pulling 16.4 ams @ 11.5v and is doing between 500-530 MH currently. Chips are running in the 60c range which is surprising with the insane chip density these boards have. The fans are also PMW controlled which is a nice upgrade since the S5 I had. Fans are actually surprisingly quiet, most of the noise is from a "wind tunnel howl" that is occurring inside the unit.

You can check out poolside hashrate here: http://www.arisechickun.com/workers 

Ill put some pics up later. Here is the status shot of the miner currently:

Yea figure that profit to be 1/3 of that by july, so plan with that in mind. Only april/may buyers have a chance of quick ROI.

Yea I got the same call...you have to send them a form and with your damn SS# because the import is valued at more than $2500 :/

Just got my units in...will be fun to tear these apart and see what cool stuff I can come up with them