Bitcoin Forum

Bitcoin => Development & Technical Discussion => Topic started by: Groc on May 15, 2011, 02:30:14 PM



Title: Can next bitcoin client limit hash/sec?
Post by: Groc on May 15, 2011, 02:30:14 PM
With the next version of bitcoin client I would like to limit the hash/sec to a trickle or what ever limit I want.

Please help me gain support for this feature.

Thanks.

Groc


Title: Re: Can next bitcoin client limit hash/sec?
Post by: Matt Corallo on May 15, 2011, 02:51:18 PM
Thats up to the miner, the in-built miner is moving towards miner removal (its already gone in GUI), though I kind of doubt it will be fully removed for a long time (if at all), no one will be adding more features to the miner in the client.


Title: Re: Can next bitcoin client limit hash/sec?
Post by: Matt Corallo on May 15, 2011, 03:41:17 PM
Quite the opposite, not having a Generate coins option keeps noobs from constantly complaining that they haven't gotten any coins and have been "mining" for a month.  Limiting khash is absolutely possible, but it should be done on the miner side.


Title: Re: Can next bitcoin client limit hash/sec?
Post by: wumpus on May 15, 2011, 03:52:03 PM
I have a pending pull request for m0mchil's miner to do exactly this, it adds a "-s <value>" option to reduce load on GPU/CPU when running the miner while doing other stuff:

https://github.com/m0mchil/poclbm/pull/10

It sleeps a fixed amount per frame, so you have to play with the sleep value a bit if you want to approximate a fixed nr of mhash/sec.

The built-in miner will never support this because it is already too slow to be of any use anyway, so it was removed.


Title: Re: Can next bitcoin client limit hash/sec?
Post by: just_someguy on May 15, 2011, 04:46:28 PM
Isn't the whole point of bitcoin to get a lot of computers to verify the transactions?

Having your CPU hash with the goal of generating a block doesn't confirm the transactions or help the network confirm them at this point. (Unless you get reaaaalllly lucky.)
Your machine will still do all the hashes necessary to confirm a transaction/block whether or not you have the generate option turned on.


Title: Re: Can next bitcoin client limit hash/sec?
Post by: Pieter Wuille on May 15, 2011, 04:58:35 PM
All nodes in the network - even those who are not lookin to generate new blocks - are verifying all transactions and blocks generated by others. This on itself is beneficial for the network (especially if you have a lot of connections).

Generating blocks is only as good as the (average) number of blocks generated. If a node would try one 1 khash per second, it will generate 1/2144027 of a block per year. Sorry, that's pointless.

The current network hashing speed is estimated around 1.8 Thash/s. It requires around 50000 normal desktop systems (4 Mhash/s each) to get a 10% share of this number. The same can be accomplished with 300 high-end graphic cards. Doing it with anything else, is just a waste of electricity.