Have you tried putting your unit in the freezer for 15 minutes before firing up BFGMiner? Sometimes different numbers of chips can come up, that might be it.

C

Yep. Keep calm and mine on.

How odd. I just bought three Sapphire cards from a vendor using Bitcoin. He showed me his QR, I put in the price, hit send, and we both agreed that it would be highly unlikely that I would be able to reverse the blockchain and double-spend the transaction.

Whatever.

C

Indeed. I looked at my old Compaq Deskpro (the one with the 486 chip that I upgraded to a Pentium 63, worst chip ever) but it's only got an ISA bus so that won't work. Now I wish I hadn't junked some of my old tower servers from the 80's, but you can't keep everything forever.

My current mining heads for 200gh of BFL weirdness is a pair of IBM x41 laptops running Windows 8.1. They actually run well, which is beyond weird.

And I just bought a 7850 on Ebay for $50, so now I have more stuff to screw with. Which means I need a board with TWO PCIx slots. :-)

C

Now you tell me. I just spent a whole $50 for a broken 5970 or whatever it is. Because I'm guessing people are blowing out the (*%#*@&%*$@&%$(& and it's not a complex fix. Maybe.

Ah well, always late to the dance :-) But it keeps me from being too bored.

C

Ok, I'm going to get started. I tell you though, if I can buy blown GPUs for peanuts and fix them due to my skillz then my life is going to be a fucking mess.

Time will tell.

C

Anyone who puts their life savings in one investment is so far beyond an "idiot" it's not discuss-able.

C

And we're back up to 700 ish this morning, too late for me to make a $400 killing. Drat.

C

Thanks I'll give it a go. I'd try the local route but I can't believe anyone would be stupid enough to sell.

Another thought: This might finally force down the price of mining equipment on Ebay so I can pick up some coins that way.

C

Ok, not to be a dingbat here, but I should probably buy some bitcoin. How do I do it without being totally scammed or wind up with three types of viruses on my system, or whatever; I basically mine my coins, and store them in my own wallets.

C

Ok, in a moment of utter stupidity I bought a broken ATI Radeon 5770 card on Ebay. Yes, I know it's garbage and broken. Yes I'm bored so I will just fix it.

But I realize the only computer I have that might have a PCI/16 slot is a 2006 era Mac G5. And that's a bit... old... to compile anything on anymore.

So the question: What is the cheapest, most useless, most pointless board I can buy that I can plug into a Corsair and a cheap-ass IDE hard drive. Hell, I could probably find a 600mb ESDI drive in the junk pile. But the point is to run something simple, small, cheap, cheap, and did I mention cheap to plug this card into and get it running.

Because I just know my next step is going to be one of those spaghetti miners with 20 GPUs mining fucking DOGE 24*7 (*). So why not start at the utter bottom of the barrel.

Thanks!
C

* DOGE! TO DA MOON!!!!!!!!!!!! MORE HAZ COINZ!!!!!!!!!

Ahem.

Never underestimate the security ramifications of a rubber hose.

The wife loves bitcoin. She went nuts on overstock.com, getting some speakers for her computer, teapot, stuff and it just magically appears. Bitcoin is like a cute little money machine upstairs.

And although it's more expensive to heat with electricity than natural gas (we have radiant heat from the 1950's godlike) these things also throw off teapots and such.

C

I don't think the top floor heat has kicked on since I fired up all these boosted miners. 220gh of power actually keeps the rooms warm at night. Come spring I'm really going to clock them down a *lot* but for now it's free heat and bitcoins!

Not sure I understand what you're asking? When you factor in shipping and such though it might be cheaper to do it locally.

C

Eh. Difficulty seems to be holding at 20% maybe less, seems that all the super miners (Monarch, Cointerra, Black Arrow, Blue Toilet, etc) are running either late or under specs.

Best way is to go to a calculation site like bitcoinwisdom, enter the parameters, and trust the numbers. Numbers tend not to lie.

Your heat sink might not be on right or contacting everything. The code will slow the chips down which will really cut the temps.

C

Probably not too far. The key in all of this is power: Once you start boosting the clock the power use in the chip starts going up geometrically. Reason being it takes more power to switch the transistors on and off as the power you're switching goes up.

USB devices have a limited amount of power avail anyway, so that's the first limiter. It's also why companies like Cointerra get in a jam: Their chip underperforms, so they boost the clock. Which puts out a *LOT* more heat but more importantly requires the 1 volt supply to switch a lot more current.

This causes the FETs to pull more power from their switching device, which is usually just a chip instead of an inverter/power driver. The switching device shorts, puts all gates closed, and all hell breaks loose as all the FETs go BOOM.

Likewise once summer hits I'm going to be clocking all my ASICs *down* to minimum speeds. They will use a lot less power, and generate little to no heat so I can run them outside. I'll lose some hashing, but I don't need the heat. Then in the fall if it's economical I'll clock them up again.

First, I would read the numbers off all six, post them, then remove them. They sometimes used different parts.

Then I would try powering it up *BUT NOT MINING ANYTHING*. The other three FETs shuould be enough to power up the chips (note they will fail on mining) but what you need to see is if there is 1 volt between that pad over on the right and ground.

If not, the driver chip is also blown and this becomes harder. If it does show 1 volt shut down immediately and order the FETs. Remember, they have solder on their backs that attach to the board so you have to heat the whole chip not just the um. pins on the ends.

C

I think cointerra is running into exactly the same problem BFL did: Chips tend to use more power than you think, and this can really upset a board layout.

In their case, I read somewhere they're hashing at 75% expected speed with more power being used. This winds up stressing the 1 volt supply lines, and since people seem to insist on running FETs in parallel (need more power, just ADD MORE FUCKING FETS) the supplies either become unstable or blow up in a cool zipper fashion.

I don't understand that bit; I've worked with electric motor controllers in the 30-150kw range and the Curtis 300 amp controllers had this hilarious bank of 30a FETs down a rail. Problem is when a FET gets warm it pulls more power, which means the rail goes unstable then the FETs start blowing up. Hilarity ensues when top and bottom rails short and you get to see if your 500a fuse is really DC rated to 30,000 amps interrupt rated.

Ahem. The right way to do it is with IGBTs, gated by a 2708 type power gate driver. A good single 300 amp IGBT would handle the 1 volt switching with very low voltage loss (ie: less heat) and can be water cooled. But do people do this? NOOOOOOOOOOO!.

So they have to redesign their board for more chips, more crosstalk, and a beefalo style power subsystem.