Noob question but what is the utility of the -b option and what is mean ?
With my GTX 770 4Gb, it is necessary to use the -b option, and if yes, how can i know what is the best value
The best (in terms of fastest) is to use the same value as N. N is currently 32768 for Yacoin. Let me explain what is going on:
scrypt-jane is running a for loop like this (which will take a loong time to complete, in the order of quarter to half a second. The GPU is fully unresponsive during that time.
for (i=0; i < 32768; ++i) { do a lot of work and memory access } // run once
-b 1024 instead runs 32 shorter for loops like this, with small pauses inbetween when interactive mode is enabled. This is the same workload as regular scrypt hashing per loop. This is why I made this the default.
for (i=0; i < 1024; ++i) { do a lot of work and memory access } // run 32 times
-b 4096 runs 8 for loops like this, which is an OK intermediate between the two extremes. This might be a good compromise for display smoothness (if you're not planning on watching movies that is).
for (i=0; i < 4096; ++i) { do a lot of work and memory access } // run 8 times
In the future, interactive mode may auto-determine the batch size to hit a desired target frame rate _exactly_.
Christian
