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.
(i=0; i < 32768; ++i) { do a lot of work and memory access }
-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-jane hashing per loop. This is why I made this the default.
(i=0; i < 1024; ++i) { do a lot of work and memory access }
-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.
(i=0; i < 4096; ++i) { do a lot of work and memory access }
In the future, interactive mode may auto-determine the batch size to hit a desired target frame rate _exactly_.
Christian