Three months pure CPU woodcutting - a challenge for GPU / FPGA / ASIC devs

Wolf0

member

Activity: 81

Merit: 1002

It was only the wind.

Quote from: funkenstein on January 28, 2015, 01:23:32 PM

Quote from: Wolf0 on January 25, 2015, 11:40:42 PM

Quote from: funkenstein on January 25, 2015, 11:34:53 PM

Quote from: Wolf0 on January 25, 2015, 10:57:06 PM

[snip]

Haha, it's an expression. That SPH implementation is pretty shitty. Skein-512 is cake to implement, though.

Tell me more

Do you refer to the efficiency in terms of hashes per cycle? Is there a better reference implementation you would recommend looking at?

It's ugly as sin. It performs okay, but hell to understand. It's also terrible on GPU - but that's not a failing of the code, more of the idiot who copy+pasted it.

lol, and now it is everywhere. Probably the most used implementation as it exists now on thousands of boxes running various multi-hash coins.

Yup. But that's okay, especially if it's on GPU, cause that means everyone's running a slow implementation Cheesy

Wolf0

member

Activity: 81

Merit: 1002

It was only the wind.

Quote from: funkenstein on January 25, 2015, 11:34:53 PM

Quote from: Wolf0 on January 25, 2015, 10:57:06 PM

[snip]

Haha, it's an expression. That SPH implementation is pretty shitty. Skein-512 is cake to implement, though.

Tell me more

Do you refer to the efficiency in terms of hashes per cycle? Is there a better reference implementation you would recommend looking at?

It's ugly as sin. It performs okay, but hell to understand. It's also terrible on GPU - but that's not a failing of the code, more of the idiot who copy+pasted it.

Wolf0

member

Activity: 81

Merit: 1002

It was only the wind.

Quote from: funkenstein on January 25, 2015, 10:45:00 PM

Quote from: ?? on ??

Quote from: funkenstein on January 25, 2015, 07:55:21 PM

Quote from: ?? on ??

Quote from: funkenstein on January 25, 2015, 04:56:50 PM

Greetings miners -

  We have now been chopping LOG for three months using only CPUs. The algorithm is pure double Skein. Is there any other coin that can claim pure CPU mining at this stage?



  Thanks --

funkenstein the dwarf

Just because the coin isn't worth anything doesn't mean it's impervious to better mining techniques - just that no one cares.

True indeed. However it appears there are people who care about hash functions and cryptography. Hence the experimental cryptocurrency. My goal in this thread is to learn something about the Skein hash function and it's applicability to proof of work consensus. I am hopeful woodcoin will help encourage folks to study this problem.

What version does it use? I know Skein forwards and backwards.

Thanks for your reply!

It uses skein512, in particular a C implementation written by Thomas Pornin. I believe this is the same implementation used by many other coins which use multiple hash functions but in this case the proof of work function is skein512(skein512(block header)).

Er, just curious.. do you really know Skein backwards? Wink

Haha, it's an expression. That SPH implementation is pretty shitty. Skein-512 is cake to implement, though.

funkenstein

legendary

Activity: 1066

Merit: 1050

Khazad ai-menu!

Quote from: Wolf0 on January 25, 2015, 11:40:42 PM

Quote from: funkenstein on January 25, 2015, 11:34:53 PM

Quote from: Wolf0 on January 25, 2015, 10:57:06 PM

[snip]

Haha, it's an expression. That SPH implementation is pretty shitty. Skein-512 is cake to implement, though.

Tell me more

Do you refer to the efficiency in terms of hashes per cycle? Is there a better reference implementation you would recommend looking at?

It's ugly as sin. It performs okay, but hell to understand. It's also terrible on GPU - but that's not a failing of the code, more of the idiot who copy+pasted it.

lol, and now it is everywhere. Probably the most used implementation as it exists now on thousands of boxes running various multi-hash coins.

funkenstein

legendary

Activity: 1066

Merit: 1050

Khazad ai-menu!

Quote from: Wolf0 on January 25, 2015, 10:57:06 PM

[snip]

Haha, it's an expression. That SPH implementation is pretty shitty. Skein-512 is cake to implement, though.

Tell me more

Do you refer to the efficiency in terms of hashes per cycle? Is there a better reference implementation you would recommend looking at?

funkenstein

legendary

Activity: 1066

Merit: 1050

Khazad ai-menu!

Quote from: ?? on ??

Quote from: funkenstein on January 25, 2015, 07:55:21 PM

Quote from: ?? on ??

Quote from: funkenstein on January 25, 2015, 04:56:50 PM

Greetings miners -

  We have now been chopping LOG for three months using only CPUs. The algorithm is pure double Skein. Is there any other coin that can claim pure CPU mining at this stage?



  Thanks --

funkenstein the dwarf

Just because the coin isn't worth anything doesn't mean it's impervious to better mining techniques - just that no one cares.

True indeed. However it appears there are people who care about hash functions and cryptography. Hence the experimental cryptocurrency. My goal in this thread is to learn something about the Skein hash function and it's applicability to proof of work consensus. I am hopeful woodcoin will help encourage folks to study this problem.

What version does it use? I know Skein forwards and backwards.

Thanks for your reply!

It uses skein512, in particular a C implementation written by Thomas Pornin. I believe this is the same implementation used by many other coins which use multiple hash functions but in this case the proof of work function is skein512(skein512(block header)).

Er, just curious.. do you really know Skein backwards? Wink

djm34

legendary

Activity: 1400

Merit: 1050

skein isn't cpu only Grin

not sure where you saw that. I am pretty sure there is already a sgminer version (and a ccminer I haven't released Grin

)

edit: double skein... well (nope I haven't coded that yet. I have only coded skein256,skein512,skein1024)

edit 2: if you want your coin to stay cpu only, don't come brag here Grin

funkenstein

legendary

Activity: 1066

Merit: 1050

Khazad ai-menu!

Quote from: ?? on ??

Quote from: funkenstein on January 25, 2015, 04:56:50 PM

Greetings miners -

  We have now been chopping LOG for three months using only CPUs. The algorithm is pure double Skein. Is there any other coin that can claim pure CPU mining at this stage?



  Thanks --

funkenstein the dwarf

Just because the coin isn't worth anything doesn't mean it's impervious to better mining techniques - just that no one cares.

True indeed. However it appears there are people who care about hash functions and cryptography. Hence the experimental cryptocurrency. My goal in this thread is to learn something about the Skein hash function and it's applicability to proof of work consensus. I am hopeful woodcoin will help encourage folks to study this problem.

funkenstein

legendary

Activity: 1066

Merit: 1050

Khazad ai-menu!

Greetings miners -

We have now been chopping LOG for three months using only CPUs. The algorithm is pure double Skein. Is there any other coin that can claim pure CPU mining at this stage?

Thanks --

funkenstein the dwarf

Topic: Three months pure CPU woodcutting - a challenge for GPU / FPGA / ASIC devs (Read 1326 times)