Bitcoin Forum
December 09, 2016, 09:40:24 PM *
News: Latest stable version of Bitcoin Core: 0.13.1  [Torrent].
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: hash algo more GPU-resistant than scrypt?  (Read 3217 times)
killerstorm
Legendary
*
Offline Offline

Activity: 994



View Profile
July 25, 2012, 10:03:44 AM
 #1

So it turns out that scrypt is barely better than SHA-256 in terms of CPU/GPU performance ratio. Maybe tuning parameters can make it better, but it seems that the whole idea isn't working. From litecoin wiki:

Quote
GPUs still do prove useful for Litecoin mining, though the improvement over CPUs is less significant than it was for Bitcoin mining (e.g. 10x speedup instead of 20x speedup).

But looking at mining hardware comparison page, difference seems to be lower than 2x.

OK, so aren't there hashes which offer higher competitive advantage to CPUs?

I'm really not an expert in this matter, but from what I know GPUs really do not like conditional jumps: with those jumps there won't be enough work for all ALUs within one stream processor. So are there hash algos which do that?

First thing which comes in mind is to make operations which are performed dependent on input itself. It might be structured in a way similar to scrypt, but with an additional step where bits of expanded input define what operations to perform on that expanded intermediate result.

Each such operation should be non-parallelizeable so that only one ALU of a stream processor can work at a time.

As a bonus it might give a relative advantage to hashing implemented in languages like JavaScript: they are already suboptimal so hit from conditional jumps is much lower.

I think there really is a case for CPU mining since it gives ordinary people a chance to mine coins for themselves. This makes sense for in-game currencies: some people really do not want to spend real money to get game money. And I guess ideally it should work well with browser-based mining so that people won't have to install anything to get money.

colored coins proof-of-concept: private currencies, stock/bond p2p exchange

Tips and donations: 16v13Fa9cPmfFzpm9mmbWwAkXY4gyY6uh4
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1481319624
Hero Member
*
Offline Offline

Posts: 1481319624

View Profile Personal Message (Offline)

Ignore
1481319624
Reply with quote  #2

1481319624
Report to moderator
markm
Legendary
*
Offline Offline

Activity: 1792



View Profile WWW
July 25, 2012, 10:54:24 AM
 #2

People can mine coins or gold or metal or whatever for themselves in games anyway if the game wants them to, its not as if they need some special weirdness to do it really, heck using greasemonkey or on MUDs a MUD-client they can even do it in games that DON'T want them to do it. So it seems like a non-existent problem. Just leave your character digging or killing monsters or whatever.

(Anyone got a MUD-client or greasemonkey that runs on GPUs? Wink)

-MarkM-

Browser-launched Crossfire client now online (select CrossCiv server for Galactic  Milieu)
Free website hosting with PHP, MySQL etc: http://hosting.knotwork.com/
killerstorm
Legendary
*
Offline Offline

Activity: 994



View Profile
July 25, 2012, 11:20:53 AM
 #3

It makes sense in game where economy is large part of the game. If currency is blockchain-based then its coinage is limited, and thus players can rely on it. (Hint: it might be a financial game.)

Also it makes sense if same currency is shared among many games.

Litecoin was geared towards that market, but now as GPU mining is available CPU mining is pretty much pointless.

colored coins proof-of-concept: private currencies, stock/bond p2p exchange

Tips and donations: 16v13Fa9cPmfFzpm9mmbWwAkXY4gyY6uh4
markm
Legendary
*
Offline Offline

Activity: 1792



View Profile WWW
July 25, 2012, 11:36:43 AM
 #4

It still doesn't matter. They can use greasemonkey or MUDclient type stuff to bake pies or weave shirts or dig up gold or whatever, and trade that in for litecoins at a trade centre / market / shop. If there is too much dug up / woven / etc then the number of coins customers will offer them per pie or shirt or nugget or whatever will be lower. There is no fundamental problem there.

In fact the game can decide ahead of time exactly how many grams of gold exist on the planet, how much in astroids, how much on other planets in the starsystem, and whether it will become possible to reach other starsystems. So again, no problem.

-MarkM-

Browser-launched Crossfire client now online (select CrossCiv server for Galactic  Milieu)
Free website hosting with PHP, MySQL etc: http://hosting.knotwork.com/
alatus
Member
**
Offline Offline

Activity: 74


View Profile
July 25, 2012, 11:45:43 AM
 #5

Games aside, I understand the question as "how to make litecoin that REALLY works and resists GPU", which is I think still a good question!
Blazr
Hero Member
*****
Offline Offline

Activity: 882



View Profile
July 25, 2012, 11:52:35 AM
 #6

CPU-chains will never work IMO. No matter what hashing function you use, an FPGA/ASIC can be manufactured that can run that function more efficiently than a CPU.

Busy ATM.
killerstorm
Legendary
*
Offline Offline

Activity: 994



View Profile
July 25, 2012, 12:28:09 PM
 #7

I don't think so, with certain hash function designs advantage of ASIC/FPGA wouldn't be high enough to justify its price.

As I understand Litecoin's scrypt is still resistant against ASIC/FPGA because adding that much memory to the chip ruins the advantage.

So maybe we can wait till ASICs dominate bitcoin mining so all GPU guys will jump to litecoin mining and BEX will suck Smiley

As I understand, scrypt isn't GPU-resistant because GPUs are not sufficiently different from CPU in sense that they do have some cache memory.

colored coins proof-of-concept: private currencies, stock/bond p2p exchange

Tips and donations: 16v13Fa9cPmfFzpm9mmbWwAkXY4gyY6uh4
Come-from-Beyond
Legendary
*
Offline Offline

Activity: 1414

Newbie


View Profile
July 25, 2012, 02:33:00 PM
 #8

So it turns out that scrypt is barely better than SHA-256 in terms of CPU/GPU performance ratio. Maybe tuning parameters can make it better, but it seems that the whole idea isn't working.

The idea is working. Quality of its implementation depends on chosen parameters. LTC just uses a wrong set of them.
ElectricMucus
Legendary
*
Offline Offline

Activity: 1540


Drama Junkie


View Profile
July 25, 2012, 07:18:28 PM
 #9

Making a hashing algo "GPU resistant" is the wrong way to go about it IMO.

The goal would be to use the available resources more consistently.
That is: instructions per second, memory bandwidth, amount of available memory.

Difficulty would be a the magnitude of the corresponding vector of all of those. Something like automated theorem proving coupled with adaptive hashing algorithm. That would be an interesting Bachelor Thesis.. give me 3 years  Grin

First they ignore you, then they laugh at you, then they keep laughing, then they start choking on their laughter, and then they go and catch their breath. Then they start laughing even more.
Ukigo
Hero Member
*****
Offline Offline

Activity: 924


View Profile
July 28, 2012, 10:44:06 AM
 #10

Partially relevant discussion :
https://bitcointalk.org/index.php?topic=44423.0
A lot of trolling and some usefull thoughts there  Smiley
Starting from :
https://bitcointalk.org/index.php?topic=44423.msg530661#msg530661
-------------------------------------------
Also, it would be interesting to ask scrypt author about his thoughts
on this topic.
--------------------------
----------------------------
You see the scrypt coins are more memory hard than the SHA coins but that's it. Their level of "memory hard"ness is static. Make a coin that has the potential to get more memory hard by offering higher block rewards to people that mine at this increasing level of "memory hard". Block rewards for lower levels of "memory hard" gradually diminish pushing miners to upgrade their hardware and and speculators to get excited about the possibility of new hardware that is faster at increasingly more memory hard math.

So make the block reward elastic but based on  the level of "memory hard" not on the difficulty. This directs the network away from energy consumption and towards technological innovation.
On the controversial note - this approach can equalify CPU/GPU/ASIC miners.
And leave "democratic" blockchain without influence of Big Money( building/buying first
expansive specialised ASICs and thus gaining controle ).

"...Enemies are everywhere ! Angka is all rage ! Be a good soldiers, blow everything... " <-- Pol Pot (C)
Ukigo
Hero Member
*****
Offline Offline

Activity: 924


View Profile
July 28, 2012, 11:28:49 AM
 #11

About non-scrypt based algos :
https://bitcointalk.org/index.php?topic=64239.msg786472#msg786472

The most promising are two last links there.  Smiley

"...Enemies are everywhere ! Angka is all rage ! Be a good soldiers, blow everything... " <-- Pol Pot (C)
phelix
Legendary
*
Offline Offline

Activity: 1680


nmc:id/phelix


View Profile
April 03, 2013, 12:07:57 PM
 #12

Also it should be changing parameters or modifying itself in a way that it can never be done as asic and hinder "compiled" gpu / fpga implementations.

blockchained.com ■ bitcointalk top posts
Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!