I presume you tried swapping power supplies at some point?

 If it's not the PS, you may have fried something in the power distribution chain on that hash board, or fried one or more of the BM1384 potentially breaking the power distribution chain to the hash unit part of the chip(s).
 Melted connectors is a BAD THING and on an S5 indicates you had a serious overheat event if you were using both connectors per board.

 S1 size cards are quite a bit taller than PCI-E cards, though a few GPU cards have fans that stick up a fair bit above the top of the board.
 S1 cards are also longer than most PCI-E cards.
 You also have a case that is almost TRIPLE the length that sidehack is trying to fit everything into. Personally, I think he should go a little longer on the case, 15" is EXTREMELY SHORT for any rackmount case and even a couple of inches of extra length would help a lot on fitting stuff in and making the air flow smoother.


 I agree that 2 cards in a row = VERY BAD IDEA, especially if we're talking 300 watts PER CARD. Rear cards are gonna overheat BADLY unless you get very fancy with air ducts and such, and then you reduce the cooling to everything.

 Ballpark 99% of the electric used by a miner would end up as heat, with pretty good efficiency at spreading it due to the heatsink and fan(s). Light from the LEDs and whatever goes OUT of the miner as communications signal(s) would be about the only part that doesn't end up as heat.



 I thought chili were grown, not mined?

 9-)

 Innosilicon has already announced tape-out on an A4 Scrypt chip.
 THAT is what is going to absolutely KILL the SF100 if SFARDS doesn't get it's act together pretty soon.

 No specs yet, but Innosilicon has this strange (for Cryptocoin hardware maker) habit of not announcing stuff 'till it's ready - the "tapeout" announcement was the first time I've EVER seen anything out of them before they were ready to sell it.

As long as Bitmain sticks with their recent "string" design choice, the only option for "undervolt" or "overvolt" adjustment is to adjust the supply voltage into the entire hash board.
 In THEORY they could put an adjustable buck converter at the power input to an entire string, but that defeats the whole purpose (simplicity AKA make it CHEAP to build) of a string design.

 Higher quality PS cost a lot more up front, unless you're willing to risk buying used units.

 220 isn't anywhere near as common in the US as 110. Most HOME miners have ONE 220 outlet available (for their dryer), many don't have any.
 You pretty much have to OWN your own home to be able to add 220 outlets, and most folks have no clue how to wire them up - at which point you're talking expen$$ive electricians to be ABLE to add any 220 outlets to your home.

 If you intend for this to be a HOME miner, ASSUME 110VAC not 220VAC or plan to lose most sales to the US (I believe Canada also defaults to 110, but not 100% certain).


 You seem to already be sizing the case around "one specific PSU".
 That would be the one advantage of specifying 2 standard ATX power supplies - even at the 1200+ watt level there are quite a few options - though they're a lot less convenient to make FIT into such a small case as you want to use.

 I don't. As many scam miner promotions as have been around for Bitcoin by now, anyone stupid enough to buy into a "preorder" from an unknown company deserves the reward for their lack of due diligance.

Intake for the PS on the TOP of the case?

 Totally NONstackable, very bad design even IF (paint that ten meters tall) they actually exist.


 Pictures don't mean squat - Alpha had lots of pictures, yet never delivered a product - among other scammers....

September 17 2015

 Wanted the 16'th but it was already taken. 8-(

On the box fan thing, just get a standard 20x20 furnace filter and fit it to the input of the fan - suction from the fan will hold it in place and it's a GOOD fit for most common box fans like that Lasko one poster linked. No need for special "fan filters".

 The one issue with putting fan filters on the S5 fans it that they reduce airflow noticeably. Good for dust reduction IN the unit, but NOT GOOD for keeping them cool. Better to keep the dust out of the room entirely IMO.

I have 2u "server" (no external drive option) cases sitting behind me with 4 80mm fans - about an inch on either side of the outside fans of clearence, quarter inch or so between each fan, and rack handles, so ballpark 3" of horizontal clearence that's not got fan in the way.

 I don't think it would be an issue to have 1" or so of one fan blowing on the PS though, don't see why 3x 120s would be a problem.

 Getting lots of airflow out of 80s is a VERY LOUD proposition - highest airflow I know of from an 80mm is the Delta 80CFM unit, which were COMMONLY known as "screamers" (6800 rpm or some such off the top of my head, those things make the 120s on a S5 sound QUIET) back when they were commonly mounted on Swiftech 370 or Alpha 8045 heatsinks on Athlon/Athlon XP CPUs.

 I don't have any of those, but I had a couple of the "next step down" 68CFM units - which were clearly audible THROUGH internal doors and the cases they were in.

 
 I'm wondering about specifying those DPS1200 - the specs I'm finding on those come out to 750-900 watts each at 110VAC depending on manufacturer, so you'd need 3 or you'd have to go 220v to power them (where they spec 1200 watts, but at that point might as well spec *1* of the IBM Bladecenter 2880 watt units instead). Is there a different DPS1200 than the ones I've been finding?

Positive pressure works a LOT better when trying to keep the air filtered, otherwise you're sucking in dust and such from every hole in your location, NOT just through the filters.

 Swamp cooling in 60%+ relative humidity is almost ineffective, waste of time don't bother with it.

 At your electric cost I'd just bite the bullet and go standard A/C - you don't HAVE to do one huge unit at a time with it, do it incrimentally as you add mining capasity. You also don't need airflow THROUGH the building if you're using enough A/C to keep the temps cool - the "mass airflow" option is for a setup that does NOT use A/C to keep temps down TO ambient despite the heat input from the miners.

 I don't think ANY current miners are set up for immersion cooling, and it's a royal pain to deal with unless your gear is specifically designed for it.
 There used to be one WATER-cooler miner out there (Bitmain Antminer C1) but I don't think it's still in production and it's a bit dated on mining chip tech anyway. Might be able to find those used though.
 It's possible to set up other miners as water-cooled, which would work well if you can dig a big geothermal-type "loop" to run the cooling water through. Still need some air cooling though for the passive components and whatever you CAN'T attach water blocks to, but that's relatively small amounts of air cooling if you can get the mining chips themselves ALL water cooled. Works better on gear that uses "big" mining chips in small numbers, like Spondoolie Rockerbock-based stuff (SP20 etc) or KnC.

You're missing the point.

 That 0.098 "electric/maintainance fee" appears to come right off the top of the "payback" part of the PACMIC contract, if I'm reading the bloody thing right. Therefore your estimate of 80 days for payback seems WILDLY optimistic, even at ZERO difficulty increase.

 I don't see where the specified 0.098 cent electric for the "optimal S5 miner" part is figured?

 I did a rough calculation last week, at 2% diff increase, and came up with ballpark 250ish days to pay back the initial .666 BTC and a small profit.

We had some mid-to-high 90s around here a week or so back. I had to downclock the S5s 'cause I'm not willing to let them excede 60C (well, I'll fudge and put up with 61-62 for an hour or two at a time if I'm at work and can't adjust them exactly). Seems like the ambient has to go over about 80 before I got to that point though, and I didn't have to downclock them a lot even in the mid-90s ambient (lowest unit I think I dropped to 325 Mhz or so from the stock 350 Mhz).

 My SP20 didn't even notice, but I've got it undervolted anyway for better efficiency (I have high electric rates 'till mid-Sept).

 No AC. 3 room fans (each in a seperate window on the downwind side of my place) on thermostats sucking air into my place through 20"x20" furnace filters (15"x24" on one window 'cause that's what fits in that window), and a couple of those "windstorm" pair-of-smallish window fans on the output window more to be sure the rain don't come in when the wind is blowing the wrong way than for any other reason.

S8 would be the BM1385 chip, if they get around to building one. If they had a "new chip by then" it would go into a S9 and S10, per their normal numbering scheme.

I suspect there are a LOT more S5 units running as pairs from the EVGA 1300G2 than there are running as singles from 750W power supplies, though the 750s offer more flexability they also eat more space.

 I suspect I'm a bit uncommon in running 3 S5s from a pair of Seasonic X1250s (I trust the longevity of most Seasonic units over anything EVGA, though the EVGA aren't BAD by any means), but that particular setup fits wonderfully well in my old 30"x12" metal storage racks (PS/S5/S5/S5/PS), there's an inch or so where the rack legs would get in the way but the PS are short enough I can work around that easily even laying them flat - just leave the exaust side pushed as far away from the "back legs" as possible.
 I'm also a firm believer in NOT pushing power supplies to their limits, both for better efficiency and better longevity (heat is THE ENEMY of anything electronic, the cooler it runs the longer it lasts on average).

 I don't understand that statement, heat sinks don't care about humidity to cool, they care about temperature differential. They do NOT use evaporative cooling like humans do.

 Ignore "heat index", that's only an estimate of how hot a HUMAN feels due to humidity level reducing the ability of a human body to cool itself, NOT the same mechanics as for an item cooled by heatsink-to-air heat transfer.




 Cost more, definitely so when you include the cost of a backplane - though not as much as you think, passive PCI backplanes do exist and have been used for a long time in some hardware and aren't exactly rare. No need to reinvent the wheel there.

 Mount really isn't any more complex than mounting those heatsinks to the case or however you're planning to mount them.

 Longevity, IME PCI connections tend to last longer than the hardware they are being used by, Heck, I've got "ancient" ISA based gear that still connects reliably after 20+ YEARS of usage. I do NOT see a longevity advantage for the typical cheap connector used on any USB setup - though I doubt it would average much if any worse, BOTH will probably outlast Bitcoin mining.

 The size disadvantage I can see POSSIBLY being an issue, especially since you're trying to limit board length for a better balance on front-to-back cooling.


 Just had a thought - but I can see mounting issues getting "interesting". Make the hash boards horizontal, instead of vertical, then mount the power supplies to one sire of the case. Would probably need a subframe mounted inside the case, or spacers between the boards, to keep the boards from flexing too much. Would give fewer but larger boards, so would be a bit less "flexable" about incrimental upgrades. It WOULD make the cooling issues on the hash boards easier to manage.

 Second thought - why limit it to 4U? As I recall BitFury and Avalon both made rack-mount 6U miners, which would make space management a LOT easier inside the case.
 6x 120mm fans on the front would generally be more airflow per square inch than 3x140 too while using a LOT more common size of fan with a LOT more options available.

 Delta, for example, does not list ANY 140mm 12V fans on their website, but they have a TON of 120mm 12V options (the 140mm fans they DO list are 24V and UP).

It's not so much that folks are mad, it's more that we want to be able to undervolt our existing S5 units *IF WE CAN* to extend how long we'll be able to mine profitably with them and give a better chance of a positive RoI on them (or give more OF a positive RoI on them if we do manage or already have managed to attain RoI on them).

 Don't even bother trying to MINE Bitcoin (or any SHA256 altcoin or any Scrypt altcoin or even any X11 based altcoin) with that setup.

 You will get VERY VERY TINY amount of coin mined, for a LOT MORE ELECTRIC COST spent. You'll lose money.

 That setup would probably never find a Bitcoin block if you ran it 'till it died - it's extremely unlikely if it would find a Bitcoin block before the last Bitcoin was mined even if the rig NEVER died.

And some you have to downclock when the temperature is too high.

 Seems like most of the "big" farms I've seen actual pictures from go with "lots of airflow at ambient" though, since it's a lot less expen$ive than paying the 20-30% more electric to use A/C to keep things cool, and just put up with having to downclock/undervolt (as applicable) during the summer. It's also a reason a lot of the REALLY big farms are being built in cool areas, when they can find cheap electric AND cool ambient temperatures (like Iceland or some parts of Scandinavia).