Quote from: ssl303 on December 29, 2013, 12:30:45 AM

Thanks again,
After I generated new address with getnewaddress on the same account, I changed the address that comes after -xpm option for each computer. However, the number that comes after "New Block:" are still the same across the all the computers. Is each computer supposed to solve different block number?
Also, I notice that it takes a long time (a day or more) for jhprimeminer to catch up to 10ch even 9ch every time I restart the process. Does it mean whenever I restart the process, I'm wasting time for jhprimeminer to catch up? Does jhprimeminer need to solve lower ch in order to get to higher ch, or is there a chance for jhprimeminer to solve 10ch before lower ch? .

The block number should be the same for all miners (for everybody in the primecoin network). What is important is that the internal algorithm is working on a different hash to find prime chains.
Regarding to your other questions I would suggest to read a little about the algorithm behind the miner from the document that was published by the creator of primecoin http://primecoin.org/static/primecoin-paper.pdf
When the miner is running you are not wasting time. Lower ch (prime chain) is a byproduct of searching for the right chain length set by the network (difficulty).