4 ms·

Bitcoin. Pay off your student loans one Merkle tree at a time.

nym 14y ago
Points for mention the merkle tree. Merklelicious!
pdog 14y ago
Serious question. How much Bitcoin could you mine on this supercomputer? Given that you don't have to pay for hardware or electricity, I imagine it would be competitive with the fastest GPU, FPGA and ASIC miners.
- Xcelerate 14y ago
  It wouldn't be as much as you'd think. For one thing, Titan uses ECC nVidia GPUs, which (if I remember correctly), are NOT optimal for producing bitcoin; AMD GPUs are better. I know you mentioned not paying for electricity, but the power bill for Titan would far exceed any bitcoin produced.
  - hn-miw-i 14y ago
    Efficency is mostly about the cost of the hardware (purchase and running costs), power usage and performance. Purchase, running cost and power usage are not part of your efficiency calculation. ATI cards have traditionally had better hashing (in general, rainbow table gen, jtr, BTC) because they have a larger number of Execution Units per core, however clocked slower, than the nvidia. Higher number of EU allows better exploitation of parallelism important for the performance of hashing. This is the fastest damn computer, its not a brand loyalty GM vs Ford, Coke vs Pepsi, Android vs iOS duality. Oh it's got nvidia, not optimized for hashing. It's going to kick the arse of any consumer or professional grade GPU on the market...
    - maaku 14y ago
      No, the point was integer-ops vs floating-point. AMD kills NVIDIA on integer-op performance, which SHA256 uses.
- hn-miw-i 14y ago
  Ok well blocks generate at an average of 1 / 15 minutes, so about 96 blocks a day. Each block generate 25 BTC reward. At ~14.00 USD/BTC on MtGox right now that about $34k. So the maximum reward in USD if you could totally control the block chain per day is $34,000. Compare hashing rate of your super computer to total mining hash rate of the btc mining swarm and that is your fraction of 34,000.
  - 0x0 14y ago
    If the fraction is > 0.5, wouldn't he be able to spoof the entire chain and collect ALL the money?
    - MiWDesktopHack 14y ago
      In practice you would need far more than 50% of the mining power to take complete control of the blockchain. The greater the hashrate of your miners, the greater probability that your miners will find a valid nonce that satisfies the difficulty equation; it doesn't magically give you the ability to find a valid nonce before any other party. As long as there is one other party mining, there is a non-zero chance that their block will be accepted before yours. What ratio of malicious/non-useful blocks vs valid, legitimate BTC transaction containing blocks would be required before the economy fails, that is an open question.
      - 0x0 14y ago
        That's for one attempt, right? How often are the nonces found?
        MiWDesktopHack 14y ago
        The bitcoin algorithm adjusts the difficulty so 2016 blocks are generated in 2 weeks, so a nonce is found every 10 minutes or so.
        0x0 14y ago
- maaku 14y ago
  Not much. There was a supercomputer that was just recently dismantled in Arizona and someone asked the same thing. I calculated a gross return of approx. $200/day. That's not counting electrical costs, which will probably put you in the red.
cecilpl 14y ago
~20Pflops = 3 terahashes/sec, which will earn you about $274/hour. Probably not the best use of supercomputer resources. :)
- hn-miw-i 14y ago
  How did you calculate that? Those units don't quite work out. It's a totally different architecture to your standard i7/radeon home mining rig.
  - chmod775 14y ago
    I don't think it's actually that different, through not as easy to calculate as e did. Quote, Wikipedia: "Titan has 18,688 nodes (4 nodes per blade, 24 blades per cabinet), each containing a 16-core AMD Opteron 6274 CPU with 32 GB of DDR3 ECC memory and an Nvidia Tesla K20X GPU with 6 GB GDDR5 ECC memory." So it's pretty much standard hardware just a lot of it. Except that the graphics card is basically a consumer tesla with some extra juice, but it's still just a card built with what's possible today. Nothing extra fancy.

nym 14y ago

Points for mention the merkle tree. Merklelicious!

pdog 14y ago

Serious question. How much Bitcoin could you mine on this supercomputer? Given that you don't have to pay for hardware or electricity, I imagine it would be competitive with the fastest GPU, FPGA and ASIC miners.

Xcelerate 14y ago
It wouldn't be as much as you'd think. For one thing, Titan uses ECC nVidia GPUs, which (if I remember correctly), are NOT optimal for producing bitcoin; AMD GPUs are better. I know you mentioned not paying for electricity, but the power bill for Titan would far exceed any bitcoin produced.
- hn-miw-i 14y ago
  Efficency is mostly about the cost of the hardware (purchase and running costs), power usage and performance. Purchase, running cost and power usage are not part of your efficiency calculation. ATI cards have traditionally had better hashing (in general, rainbow table gen, jtr, BTC) because they have a larger number of Execution Units per core, however clocked slower, than the nvidia. Higher number of EU allows better exploitation of parallelism important for the performance of hashing. This is the fastest damn computer, its not a brand loyalty GM vs Ford, Coke vs Pepsi, Android vs iOS duality. Oh it's got nvidia, not optimized for hashing. It's going to kick the arse of any consumer or professional grade GPU on the market...
  - maaku 14y ago
    No, the point was integer-ops vs floating-point. AMD kills NVIDIA on integer-op performance, which SHA256 uses.
hn-miw-i 14y ago
Ok well blocks generate at an average of 1 / 15 minutes, so about 96 blocks a day. Each block generate 25 BTC reward. At ~14.00 USD/BTC on MtGox right now that about $34k. So the maximum reward in USD if you could totally control the block chain per day is $34,000. Compare hashing rate of your super computer to total mining hash rate of the btc mining swarm and that is your fraction of 34,000.
- 0x0 14y ago
  If the fraction is > 0.5, wouldn't he be able to spoof the entire chain and collect ALL the money?
  - MiWDesktopHack 14y ago
    In practice you would need far more than 50% of the mining power to take complete control of the blockchain. The greater the hashrate of your miners, the greater probability that your miners will find a valid nonce that satisfies the difficulty equation; it doesn't magically give you the ability to find a valid nonce before any other party. As long as there is one other party mining, there is a non-zero chance that their block will be accepted before yours. What ratio of malicious/non-useful blocks vs valid, legitimate BTC transaction containing blocks would be required before the economy fails, that is an open question.
    - 0x0 14y ago
      That's for one attempt, right? How often are the nonces found?
      - MiWDesktopHack 14y ago
        The bitcoin algorithm adjusts the difficulty so 2016 blocks are generated in 2 weeks, so a nonce is found every 10 minutes or so.
        0x0 14y ago
maaku 14y ago
Not much. There was a supercomputer that was just recently dismantled in Arizona and someone asked the same thing. I calculated a gross return of approx. $200/day. That's not counting electrical costs, which will probably put you in the red.

cecilpl 14y ago

~20Pflops = 3 terahashes/sec, which will earn you about $274/hour. Probably not the best use of supercomputer resources. :)

hn-miw-i 14y ago
How did you calculate that? Those units don't quite work out. It's a totally different architecture to your standard i7/radeon home mining rig.
- chmod775 14y ago
  I don't think it's actually that different, through not as easy to calculate as e did. Quote, Wikipedia: "Titan has 18,688 nodes (4 nodes per blade, 24 blades per cabinet), each containing a 16-core AMD Opteron 6274 CPU with 32 GB of DDR3 ECC memory and an Nvidia Tesla K20X GPU with 6 GB GDDR5 ECC memory." So it's pretty much standard hardware just a lot of it. Except that the graphics card is basically a consumer tesla with some extra juice, but it's still just a card built with what's possible today. Nothing extra fancy.