Thread about GPU-mining and Litecoin

[dishwara]

I am not a follower of coin hunter or solid coin & all their stuffs...........

I saw in my own eyes, a 5870 mining litecoins, & i put screen shot.
For those who still saying no proof, better download & try urself.
http://solidcoin.info/reaper.html

First they CPU mined bitcoins & thought nothing is there other than CPU, then GPU mining came to bitcoins & even FPGA.....

The question now is first it was told its only CPU mining, but now GPU also can mine them.
Profit or loss is another question. Can GPU mine litecoins? Yes.

Now what Litecoin developers going to do about GPU mining?  

[1714834410]

1714834410

[1714834410]

1714834410

[pooler]

Current algorithm is:

1) Calculate B = SHA256(A)
2) Calculate C = scrypt(B)
3) Calculate D = SHA256(B, C)
4) Return D

Not really. SHA256 is part of scrypt. The sequence looks more like this:

1) PBKDF2 using HMAC-SHA-256
2) Memory-hard mixing loop using salsa20/8
3) PBKDF2 using HMAC-SHA-256

Something I've wondered:

Why are you using N=1024, r=1, and p=1 for scrypt?  Why didn't the recommended values from the paper, N=1024, r=8, p=1 get used?

If I remember correctly, ArtForz said that the parameters (1024, 1, 1) resulted in a lower GPU/CPU performance ratio.
Some analysis by him can be found here: https://bitcointalk.org/index.php?topic=45849.0

http://solidcoin.info/reaper.html

What looks interesting is that they still claim the SC2 algorithm to be GPU-resistant. I'm not at all convinced. Any technical opinion on this?

[Balthazar]

Current algorithm is:

1) Calculate B = SHA256(A)
2) Calculate C = scrypt(B)
3) Calculate D = SHA256(B, C)
4) Return D

Not really. SHA256 is part of scrypt. The sequence looks more like this:

1) PBKDF2 using HMAC-SHA-256
2) Memory-hard mixing loop using salsa20/8
3) PBKDF2 using HMAC-SHA-256

Yes, salsa20/8 generates "password salt" for second PBKDF2 call. I mean, that new algorithm can use bcrypt() before second PBKDF2 call. This will be VERY slow and L1 cache-dependent. 

[localhost]

I saw in my own eyes, a 5870 mining litecoins, & i put screen shot.
For those who still saying no proof, better download & try urself.
http://solidcoin.info/reaper.html

Doesn't work for me: always times out when trying to reach the pool...

[shakti]

I saw in my own eyes, a 5870 mining litecoins, & i put screen shot.
For those who still saying no proof, better download & try urself.
http://solidcoin.info/reaper.html

Doesn't work for me: always times out when trying to reach the pool...

hostname used should be without prefix http://

[shakti]

http://solidcoin.info/reaper.html

What looks interesting is that they still claim the SC2 algorithm to be GPU-resistant. I'm not at all convinced. Any technical opinion on this?

It's not GPU resistant, but random reads on constant 4MB buffer make the difference of CPU/GPU slightly lower cause GPU lucks on a lot of cache. But it's still 4-6 times faster on GPU as on CPU

[localhost]

Doesn't work for me: always times out when trying to reach the pool...

hostname used should be without prefix http://

I tried both: with http, without http, also with IP instead of host name, different ports (using pool-x so I could try port 80, 8080, etc), nothing worked

[3phase]

Given that it's currently not worth it to mine LTC using GPU, having a GPU miner out is not going to change much. But there are few potential problems I can think of:

1) This puts a cap on LTC price. When LTC price rises to make GPU mining profitable, we will see a bunch of people switching their GPU farms to Litecoin and sell the mined litecoins for bitcoins. This will put a downward pressure on Litecoin price. This is not necessarily a bad thing, because price doesn't matter that much.

2) Could lead to wild swings in difficulty as GPU miners move in and out of Litecoin mining. This will be similar to what happened with Namecoin before the merged mining. But since Litecoin retargets at 1/4 the time as compared to Bitcoin (3.5 days as oppose to 2 weeks), the swings shouldn't be that painful.

3) GPU mining makes it easier to 51% the chain. It would be easy for a decently sized GPU farm to 51% the chain.

I think I'm most worried about the last one.

Number 2 is the biggest danger. With the next Litecoin retarget, as long as price stays above 0.0015, it will be more profitable to mine LTC (yes, with that closed source miner). Maybe not this time around, but by the next time when more people will have heard of it, you could get a few hundred MH/s switching to LTC mining, reach retarget with a 4x difficulty in a few hours, and then they leave, which will then make it very difficult (2 weeks or more) for the rest of the miners to fix by retargeting to a lower (0.25x) difficulty. Also take into account that, at this point, it will be largely unprofitable to mine LTC even with GPUs, so you might have even more miners shutting down.

The difficulty swings that happen because of exchange rates have been proven to be non-converging. Profitable difficulty periods get shorter and unprofitable periods get longer. It happened to NMC, I0C, IXC, FBX and TBX in the same way.  Eventually the chain dies, unless merged mining takes over. In LTC's case this is not possible.

We shall see. It will be at least interesting to watch.

[localhost]

I saw in my own eyes, a 5870 mining litecoins, & i put screen shot.
For those who still saying no proof, better download & try urself.
http://solidcoin.info/reaper.html

Doesn't work for me: always times out when trying to reach the pool...

On a side note, anyone knows why the GPU miner tries to connect to load.squidnet.org (96.8.126.110) from port 51100 to port 12000?

[Fuzzy]

Doesn't work for me: always times out when trying to reach the pool...

hostname used should be without prefix http://

I tried both: with http, without http, also with IP instead of host name, different ports (using pool-x so I could try port 80, 8080, etc), nothing worked

Same here, tried 4 pools, nothing would connect.

A hoax to instill uncertainty in a competing crypto currency? Given how outspoken the SC team are against LTC, I don't see why they are holding back with Demo versions if they have a real opportunity to cripple a competitor.

[localhost]

I tried both: with http, without http, also with IP instead of host name, different ports (using pool-x so I could try port 80, 8080, etc), nothing worked

Same here, tried 4 pools, nothing would connect.

Since "localhost" was the default option, I even tried solo-mining: failed to connect too.

[dishwara]

u have to put it in litecoin.conf & just run reaperdemo.exe without any arguments.
Litecoin.conf for
host mine.pool-x.eu
port 9332
user urpoolname with worker like xxx.1
pass ur password for pool

[localhost]

u have to put it in litecoin.conf & just run reaperdemo.exe without any arguments.
Litecoin.conf for
host mine.pool-x.eu
port 9332
user urpoolname with worker like xxx.1
pass ur password for pool

That's what I did, it didn't work (timeout). Note that the pool wasn't down as my other worker could connect to it without problem.

And this doesn't explain why the miner sneakily connects to another pool, as I detailed in post 118.

[dishwara]

No idea. Its not connecting connecting sneakily another pool in my system.
It seems your download is affected with some virus or trojan or any other malwares.

I too got first timeout error, then weird server problem error, library error..........

[localhost]

No idea. Its not connecting connecting sneakily another pool in my system.
It seems your download is affected with some virus or trojan or any other malwares.

I did download from there, though: http://solidcoin.info/reaper.html. I don't have the file I downloaded on this very computer, I'll post md5sum of the file I grabbed tomorrow, if someone wants to compare with their own hash. Also, I didn't check what it tries to communicate to the pool, maybe it's just pinging and sending nothing. But there's some kind of connection attempt.

[Fuzzy]

I have Radeon 6950s on Win7 x64 bit, and this GPU miner doesn't actually work. It either crashes, or fails to connect.

Also, the fact that the LTC network hash rate DROPPED after the release of this "demo" suggests this is a HOAX, and not actually able to submit legit shares for mining LTC

[Rubberduckie]

It works for me,solo mined 2 blocks so far

(mining with a 6970 @ 262 Kh/s)

[localhost]

No idea. Its not connecting connecting sneakily another pool in my system.
It seems your download is affected with some virus or trojan or any other malwares.

I did download from there, though: http://solidcoin.info/reaper.html. I don't have the file I downloaded on this very computer, I'll post md5sum of the file I grabbed tomorrow, if someone wants to compare with their own hash.

If anyone wants to compare with the files they downloaded, here are my md5 hashes

Code:

7220844fab32072fc4279436f330bb76  litecoin-reaperv13_demo.zip
7bc0ee636b3b83484fc3b9348863bd22  litecoin-reaperv13_demo\litecoin-reaper.cl
0f6e06a7cd747d317f7c8b441e0cd946  litecoin-reaperv13_demo\litecoin.conf
5757f08f18556c6cf1beabb51579cfa1  litecoin-reaperv13_demo\curl.dll
53cf7caa93ca6d827061d67719a99c34  litecoin-reaperv13_demo\litecoin-reaperv13.Cayman.bin
3cd768d7dd0874b8ea6639aa0ac03a5f  litecoin-reaperv13_demo\litecoin-reaperv13.Cypress.bin
544f3050ffe55e6b423695331e581bbd  litecoin-reaperv13_demo\reaper.conf
3a86a0088cc1e05a54c5d2708ecb2f9d  litecoin-reaperv13_demo\pthread.dll
f010428b110180e138d15e8ba1839c59  litecoin-reaperv13_demo\reaperDEMO.exe

[dishwara]

7220844fab32072fc4279436f330bb76     reaperv13_demo.zip

  File: reaperDEMO.exe
CRC-32: 4e6b6859
   MD4: abef30ed97d4f51e483b4e27fa489138
   MD5: f010428b110180e138d15e8ba1839c59
 SHA-1: 67e578532d90acef5793e41c53c74c2c8b07a662

[localhost]

7220844fab32072fc4279436f330bb76     reaperv13_demo.zip

Looks like we do have the same one... did you manage to get it working in the end?