The name of the game in mining Bitcoins isn’t CPUs, GPUs, or even FPGAs. Now, hardcore miners are moving on to custom ASIC chips like the Block Erupter, For around $100 USD, you too can mine Bitcoins at 300 MH/s with 2.5 Watts of power and a single USB port. This speed isn’t enough for some people, like [Jeremy] who overclocked his Block Erupter to nearly twice the speed.
[Jeremy] begins his tutorial with a teardown of the Block Erupter hardware. Inside, he found a custom ASIC chip, an ATTIny2313, a USB UART converter, and a voltage regulator for the ASIC. By changing out the 12 MHz crystal connected to the ASIC and fiddling with the voltage with a trim pot, [Jeremy] was able to overclock the ASIC core from 336 MHz to 560 MHz. Effectively, he’s running two Block Eruptors for the price of one with the potential to actually make back the purchase price of his hardware.
It must be noted the 560 MHz figure comes from replacing the 12 MHz crystal with a 20 MHz one, and this mod only lasted about 20 minutes on [Jeremy]’s bench until the magic blue smoke was released. He recommends a 14 or 16 MHz crystal, netting a new speed of either 392 MHz or 448 MHz for a stable mod.
38 thoughts on “Overclocking Your Bitcoin Miner”
all we need now are the extreme cooling mods
So If he left it stock and let it run for an hour he would have been ahead of the game. How long will it take for the next one to make up the cost of the one he killed?
This is why you slowly turn up the wick to see how fast you can overclock a device, instead of attempting to run it at nearly double factory spec right out of the gate.
I did start off slow with 12.5mhz, then 13mhz and 13.5mhz. Then I found a 15.36mhz crystal on a scrap board i had laying around. After playing around with that for a day being semi stable I moved on to 16mhz. I couldn’t find any other crystals between 16-20mhz so i bit the bullet and went all out. This wasn’t a 1 day thing, I spent almost a week testing things out and changing the crystal circuit. One thing I want to try is to abuse a ATtiny24 for its crystal oscillator circuit and see if I can steal the clock signal off it :)
The problem with overclocking this type of system is verifying it is working correctly when you overclock it. With a computer you can interact with it and it is quite obvious when it doesn’t work right. With a bitcoin miner it just sits there and it may actually pass over a valid bitcoin because it isn’t working right.
Simple. Just attach your miner to a bitcoin mining pool, and look at the pool estimate of the hashing speed. The nice thing about bitcoin mining is that a small amount of errors, say 1%, is perfectly acceptable.
not if a bit coin falls in that one percent. You will have done all that work for nothing.
I don’t think you understand how Bitcoin actually works. A roughly 60% gain in clock rate is very desirable even at a 1% error rate, since you still have a much higher probability of producing a block.
All that matters is how many good hashes per second you can do. If a standard device does 300 MH/sec with 0% errors, and an overclocked device does 400 MH/sec, with 10% error rate, it’s still doing 360M good hashes per second, which is better than 300M. An error in one hash does not affect the other hashes. In a mining pool, you get credited for each share (on average it takes 4GH to produce one share).
Er actually that is NOT correct…..
All that matters is the NUMBER OF NONCES produced that meet/beat the difficulty.
you could have a device capable of 3TH/s but if it produces ZERO matching nonces it is WORSE than a device running 300mh/s that produces three nonces.
The problem with over clocking is that you do not know how many QUALIFYING nonces you are trashing..
The ONLY way you can measure it is to have a device that processes exactly the SAME work at a much slower rate to compare against…
A working example…
I ran an FPGA ..way…way over clocked, the ‘error’ rate was 0.2%, that is to say out of 1000 nonces produced 2 were bad…
BUT on checking with chipscope, I found that the over clocking was setting the high bit on during the comparison to meet the diff1 over 20% of the time…
Which means that my loss was actually 20.2% , of GOOD nonces…
Externallly it looked like 0.2%… but internally (something you cannot see without an internal probe) it was >20%
Better you actually UNDERSTAND what you are talking about, before commenting….
300 MH/s Mega-Henries per second?
Mega Hash per second
That’s very little for $100.
Indeed. At the current rates, 300MH/sec will get you $3 in a week, but earnings are dropping about 10% per week. Extrapolating that curve, you can expect something like $30 total return.
Does he know why the blue smoke came out? Was it just overheat or some other mechanism?
I have no exact reason for the failing of the asic. Although I have a feeling that the 5v clock signal boards may have been a ticking time bomb waiting to destroy the chip.
My next test I am planning on using a raspberry pi with voltage sensors on the asic core voltage lines and i2c temp sensors to monitor the stats of the block erupters at all times :)
Lot of very poor research in that article. Arctic Silver isn’t conductive and hot glue is a godawful way to attach a heat sink. Not only is it flexible at room temperature which reduces pressure against the chip, but loses bond strength as the temperature increases. I’ve seen half a dozen people use hot glue to attach sinks only to have them fall right off when they need them most. The fact he didn’t bother to monitor the temperature as he increased the overclock is also disturbing as he has no idea what actually killed his Erupter.
I remember from past experience that various versions of Arctic Silver were electrically conductive.
From their website
“Arctic Silver 5 was formulated to conduct heat, not electricity.
(While much safer than electrically conductive silver and copper greases, Arctic Silver 5 should be kept away from electrical traces, pins, and leads. While it is not electrically conductive, the compound is very slightly capacitive and could potentially cause problems if it bridges two close-proximity electrical paths.)”
So even with the latest version they have out, you run into issues with messing up the capacitance on the board.
You should be able to find some thermal adhesive that will stick the heatsinks to the appropriate chips while still conducting heat efficiently.
I have a cooling solution. It is actually cooling 3 block erupters together, and your points about thermal glue are pointless, just screw the device to the heatsink. anyway I would love to modify my erupters email me for more details.
I have a perfect cooling solution, I had created it myself, it is designed to cool 4 erupters at once.
Is it placing an ice cube on them and blowing?
Positive smoke test!
frying such a board… no words.
Assuming you don’t over clock, what is the roi time for the block eruptor?
IIRC, negative. More info in bitcoin forums.
Over a year @ the current difficulty trend. The price is way too high on these right now once some competition get into the market prices should go down. I paid a bitcoin for each of mine several months back and have yet to mine a bitcoin between the two even after overclocking.
16mhz crystal is stable over long periods. I’ve had my miner going for weeks like this. Check out the thread on bitcoin talk https://bitcointalk.org/index.php?topic=241652.0
What value resistors did you select for upping the voltage? What 16mhz crystal did you use?
So basically his Block Eruptor erupted.
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I have a Dell with a Intel HD Graphics 2500. I was wondering if this is the CPU or a separate chip on the motherboard. I know i should use a graphics card but im going to start out small and then buy one. When I started to mine i Noticed a chip on my motherboard getting Very hot. Would that be the GPU? It has no fan so if it is i want to put one in. Could anyone help?
Honestly, you’re wasting your time mining with an intel graphics on-board vid. Its a chip on your mobo, but really only super high end graphics cards give you any kind of real POWER for mining.
The discussion here is about a specific piece of hardware called an erupter – its a little usb chip that plugs in and will dedicate itself to mining – at around 300 M/H per second…(by comparison, I originally used guiminer for fun just to see what I could get on an intel hd 4000 and I got around 17 M/H per second). Also, look into what bitcoin mining pools are – going at it alone even WITH the right hardware will get you nowhere.
there cheap now you should try again
He who makes light sees no more than he who doesn’t.
He who makes light shines it into the eyes of he who doesn’t, temporarily blinding him, then steals his bananas.
Now that these things are very cheap I’ve taken a stab at overclocking the Block Erupters. Here are my findings: https://plus.google.com/103650403987899280833/posts/DF5s54J34fb
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