CGMiner won't talk to my Jally; apparently the problem is some sort of timing error, it works fine with my erupters. So I'm back on BFG, and blind as to the details of my JP. Oh well.

FF: Sorry you blew up your JP, can you post what kinds of temps you were running and error rates? Every time I tried to move above 7 the unit would generate more heat, a lot more errors (5-10%), and not a lot more hashing. It's back to stock speed 7.4gh or so 43c, 2.6% error rate, and 335.7mh/s, 1.6/.91% error rate on the two erupters.

So an overall hashing rate of 8gh/s.  I can live with that although with the difficulty change I just dropped from .05btc/day to .03btc/day. Ah well.....

And the difficulty just went up and my rig went from .05btc/day to .03btc/day.

Sorry, Bitcoin mining is a queen's race. People are not good at spotting that.

Human nature.

C

I'm serious: One way to fix the whole ROI thing is to use the miners for extra work loads that can generate profit.

Like water heating. So who is going to take an old copper hot water solar panel, affix 100 block erupters, and sell it to someone to use to heat their household water and mine bitcoins in the background?

Bitcoin space heaters? How about a Bitcoin oven for the kitchen?

C

Indeed. I've found that going beyond 7 does weird things for my Jally; staying at 7.3gh. Did note that uing the Artic heat pad has reduced my temps to 40c, which is very nice actually. And I found a 10 pin header that I am going to sand down to fit under the sink so I can stop taking it off all the time. Want to flash on demand. :-)

Speaking of which, is there a way to identify the number of active cores using BFGMiner, or do I have to install CGMiner?

Exactly. I should get cgminer running so I can see how many cores are running on each CPU, and if that changes by my moving the diagnostic level from 10 to 1. Right now I backed out my 8 change yesterday to 7, left the diagnostics set to low, and am getting 4% failures on the bad chip instead of the 2% before. So I might have enabled another core that is throwing 2% errors overall on the chip.

The trick with running faster is it burns more heat, it seems to be going up exponentially and not linerally as I clock up, more heat=more wear=more power (which is a hill of beans right now, even with the laptop the whole shooting match only pulls 40 watts).

Next up is to try powering the system off a 12 volt battery to see if a perfectly smooth power input reduces errors. If some of the error is caused by instabilities due to the cheap-o-power supply, clean DC might mean more cores to bear which would mean more $$$$

C

Define through the roof? I don't think error work is sent back; I think it's just dropped. Mine now is 2.5% overall, 0% on one chip, 5% on the other. But in a technical sense, a chip core that is 25% bad is still doing 75% of the work and contributing to my overall dollars.

Perhaps.

C

Likewise, if for nothing else I can float off the BGAs and put them on my Jally. However like everything else in the bitcoin world, it's a matter of calculations:

Estimated chance of repair * value of unit in mining bitcoins=max price you should pay.

Given that difficulty is screaming up, time to repair needs to be factored in as well as these things are losing their ability to make value by the second. Then again that is reflected in "value of unit" :-)

And of course add in the "entertainment factor" for being able to play with one. But the emotional factor of "oooh I have a jally!" would be zero for me since I have one, so it will probably go to someone who wants a jally at any cost less than what you can get it for on Ebay.

I went through the same mental math with a block erupter on Tuesday. I'm going to strap it to my house's water pipe inlet and use it to pre-heat water, so it has a practical value (hah). :-)

C

Quite possibly: put the ASICs inside a copper waterproof tube that goes into the water heater, then use either direct-connects to the tube walls or heat pipes to conduct the heat to the walls.

The only issue then becomes how hot can you run the chips, and how hot do you like your water? If the chip temp limit is 140 that's the max temp your water can be at. The other issue of course is the thermodynamics behind heat transfer at dissimilar temps, the closer the two plates are to same temp the less heat that can be transferred. Hm.

Maybe what this needs to be billed as is a "pre-heater tank". That's it: You build a say 5 gallon copper tank, then line the *outside* of it with ASICs, then insulation. It takes the cold water from the utility, heats it up as much as it can, then when you turn on the faucet it goes into the bottom of the main tank where your electric heater can finish boosting the temp to household. Stratification is limited by water coming in and out.

If you want to run this contraption 24*7, you put a small heat exchanger in the tank, connected to a radiator outside the insulation zone. Kick on that pump if water temp >120 or something. But in this thought experiment the main goal is to heat your house water for less by subsidizing your heat with bitcoins.

I may actually try this with an erupter, heat sink it to the copper inlet pipe on my water system, right across from the expansion tank (to increase the water sinking mass). My wife is going to love me.....

C

Just took a look at the pics. That repair is going to be fun. My guess is the repair person used a big soldering iron at way too high a temp, the pad just fell off. Probably easier to do a bypass wiring at this point.

Ah well. Do-able with air tools, but not simple. I've repaired blown up IGBT drivers that did things like that, at least there are no shorts inside the board :-)

And as a side note: I took apart my Jally this evening for the daily flashing of the code (can't help it, tweak tweak) and noticed that with the board on the floor and a USB cable plugged in that any pressure on the board would cause a serious amount of torque on the USB plug. So I put my board sideways so it would not break.

I could see that happening by accident. Pretty easily. So if you're tweaking, be careful of that connector outside the box; it has limited support.

C

This thread inspired me, so after getting my 5gh/s jally last Tuesday I ran it (5.1gh/s, 34 C), and ordered a Dragon.

Dragon came on Tuesday, flashed the unit with the stock 1.25 firmware (speed 7) and performance went to 7.3gh/s. Nice. Temp went to 40c, I noticed one chip was putting out 3% error rate, other was at zero %.

This evening I flashed it with diagnostics set to one (to try to get more cores), speed to 8. Performance is around 7.7gh/s, Temp is 45C, one chip is putting out close to 9% error rate.

Looks like one of my chips is a tad bit substandard. Not sure if going to 9 will speed me up more or overwhelm the slower chip, but in either case the heat increase is substantial.

I've ordered some artic heat sink pads to replace the wimpy ones on the unit now, but for a $169 or whatever I paid for this when I ordered it in Jan it's not too bad. I might back the speed back down to 7 since the higher error rate might not be worth it, or should I go to 9?

Thank you everyone for the help.

Any idea when they will come in? I don't need 48, but it would be interesting to pop 2 of them on my new (and so being taken apart and played with) Jally.

C

Just got my BFL Jally last week (ordered in Jan for $180 or so) and already I feel like a pro. Monday I got my dragon programmer, and I was up till 1am clocking it up from 5 to 7.5gh. Then difficulty changed, it's all my fault.

So of course today I just bought an erupter for $38.00, was $45 last week, but difficulty just hopped. :-)

Why?

Well, first I have an open USB port here. But more to the point, winter is coming on, and I need to keep the top floor warm. Normally I would use gas heat with a 1.5kw heater as a supplemental. However my Jally is now dissipating 30w of heat (up from 20), and each erupter can generate 5 watts or so? That will reduce the need to use the heater, and "make" money.

So think of it this way: You have an electric water heater in your basement? Pull the filament and heat it with erupters. No wait, make a heating element *out of* erupters that you can put in the tank in place of the heater that's there now. 4500 watt element would be 900 erupters. That's a 300gh unit that you can use forever to heat your water and it will make bitcoins! Why use a heating element? :-)

Bitcoin is less like a prisoner dillema and more like a dollar auction. I mine because it's entertaining.

C

Update: I shut it down, opened it up, snugged down the bolts on the heat sink plate a bit tighter, and fired it back up. Temps are now at 46c, bit better. 7.5ghs speed, 1.9% error rate (down from 3%).

I'll grab some fujipoly next before screwing with the settings to boost speed.

Morning!

Well, we all have to start off as newbies, so here we go:

I got my 5.0gh/s Jally on Friday of last week and ran it through the weekend with BFGminer. Hashed at about 5.0gh/s, just what I paid for. Temps on the unit were a nice cool 38 degrees C. Unit pulled 20 watts with a power factor of .59 (these power supplies are garbage) with a laptop the whole thing pulled 40 watts with the E-meter.

This evening my dragon programmer came from China (ordered Saturday) and of course I had to flash this thing. I've worked on 68HC711K4 type chips and can deal with programmers so I installed studio, flashed the firmware on the dragon, dug out an old 12 pin header cable, tore apart my jally (had to remove heat sink), and got to it.

The heat sink came off with the pads still on it. Chips were super clean. Hooked up the programmer, followed the directions including setting Device=AT32UC3A1128, and formatted the chip. No problem, Jally rebooted to dead.

Then I tried to load the code and failed. Badly. CRUD! So I broke out the hacker helmet, did some poking around and found that my jally has an AT32UC3A1256 chip instead. Very nice of them to give me more memory, but it was close enough to format, not close enough to load.

Loaded the code, put the heat sink back on (snugged the screws down to as snug as they were when I removed them, IE finger tight), fired it up, and it's running at a nice solid 7.5gh as reported in BFG but a temp of *50* C. Pulling a total of 10 watts more as measured by the P3 meter.

So if you're going to do this with a newer Jally, keep in mind the AT chip might be different. Also keep in mind that the temps seem to be higher, and I am not thrilled with this.

Now for the question: Should I put some artic silver or other heat sink compound on the chips before replacing the sink (IE go in there and fix it right)? I don't like hot components, and the heat sink should probably be pulling more of the heat on those chips. But I do not want to tighten the screws, that's the #1 way to break chips.

Hm. I do have that big copper heat sink from my old IBM X366 somewhere....

CZ