Is it true that 2 instances of a miner running at 500k hashrate, would find the same number of block of 1 miner at 1000k hashrate?
I bought a second GPU and I read you can mine with 1 or 2 instances of cgminer (thats what I use for scrypt mining) and the hashrate is the same, but should the probability of finding a block be better if you do not use 2 separate instance? That would also required the miner software "split" the work correctly on each GPU, which maybe they do not do it, so it does not matter 1 or 2 instance?
From my very basic understanding, for each block the first miner to find the 32 bits random digit get the reward. If that is so, then 2 GPU running on 2 instances, may/will have some duplicate work, they may or will check for the same numbers during the block search?
If the 2 GPU were working together, then they should be more efficient? As they can split the work and not check the same numbers?
This is a good question. My guess is that it makes no difference what you do.