OK, so I have a question about this 120 second invalid share thing.
I understand this is the default value in the software, but WHY? Why is an otherwise valid share that takes 121 seconds to generate tossed in the trash? A 119 second solution that solves a block is fine, but a 121 second block solving solution is not?
From reading the forums, my best guess is that this was originally put in place way back in the dark ages to discurage the use of _very_ slow (read: CPU) miners. Well, thats great if the dificulty is only 100K, but now that the dificulty has increased nearly 20-fold, shouldn't this warrent a second look?
A miner putting out 80 Mhash may not exactly be top of the line, but it is still very viable if you get rid of the 120 second limitiation.
Also, it seems to me that if you have a miner that supports long-polling, the 120 second limit becomes completely pointless.
Are there some system resource issues on the back end that I'm not aware of? Or something like that?
Since I'm stuck in newbie-land, if someone could re-post this to the main thread, it would be appreciated.
thanks,
Sigg
I missed this post earlier, so I'll reply to it now. I don't think it has anything to do with excluding CPU miners. Although a CPU has less power than a GPU, CPU miners still contribute to the network security. Maybe even significantly, because there are so many more CPUs out there than GPUs. It just wouldn't be healthy to exclude CPU miners. I understand this is the default value in the software, but WHY? Why is an otherwise valid share that takes 121 seconds to generate tossed in the trash? A 119 second solution that solves a block is fine, but a 121 second block solving solution is not?
From reading the forums, my best guess is that this was originally put in place way back in the dark ages to discurage the use of _very_ slow (read: CPU) miners. Well, thats great if the dificulty is only 100K, but now that the dificulty has increased nearly 20-fold, shouldn't this warrent a second look?
A miner putting out 80 Mhash may not exactly be top of the line, but it is still very viable if you get rid of the 120 second limitiation.
Also, it seems to me that if you have a miner that supports long-polling, the 120 second limit becomes completely pointless.
Are there some system resource issues on the back end that I'm not aware of? Or something like that?
Since I'm stuck in newbie-land, if someone could re-post this to the main thread, it would be appreciated.
thanks,
Sigg
I also don't think long-polling changes the situation regarding the age-limit.
A much more logical reason is that old work causes the pool to miss out on transaction fees. How is that? New transaction (and their fees) keep coming in over time, and make the next block more valuable with every second that passes since the previous block. If someone hands in work that is 120 seconds old, that solution will not contain the transactions from the last 120 seconds. Remember that there are on average only 600 seconds between blocks. This means that work that is 120 seconds old misses out on (on average) 20% of possible transaction fees. Those 20% are passed on to the finder of block n+2 however, so the effect cancels out. Unless there is some pool that decreases or increases its age-limit, because that will shift the fees in favor of one of the parties.
Since most pools seems to use 120 seconds, ABCPool will do the same. This keeps the whole ecosystem in balance.
