if you want to test or get your probably best speed try benchmarking first
hashcat -b -m 12500
do 3-4 runs and get the expected full-speed of your hardware, quick test with a normal pc
Hashmode: 12500 - RAR3-hp (Iterations: 262144)
Speed.#1.........: 1420 H/s (67.45ms) @ Accel:32 Loops:16384 Thr:1 Vec:8
Speed.#3.........: 192 H/s (69.96ms) @ Accel:2 Loops:16384 Thr:64 Vec:4
Speed.#*.........: 1612 H/s
the 1420 hashes or 192 hashes is the best speed "i" can expect for GPU, CPU when attacking mode 12500
so just try it for yourself and see whether or not your actual cracking speed of 20300 hashes is near your best benchmark for -m 12500
if yes, then yes, this is the best speed you can expect, if not, maybe your mask of length 6 is still "to short" for parallel work on your gpu
be aware most hashmodes with high iterations are considered to be slow
hashcat -b -m 12500
do 3-4 runs and get the expected full-speed of your hardware, quick test with a normal pc
Hashmode: 12500 - RAR3-hp (Iterations: 262144)
Speed.#1.........: 1420 H/s (67.45ms) @ Accel:32 Loops:16384 Thr:1 Vec:8
Speed.#3.........: 192 H/s (69.96ms) @ Accel:2 Loops:16384 Thr:64 Vec:4
Speed.#*.........: 1612 H/s
the 1420 hashes or 192 hashes is the best speed "i" can expect for GPU, CPU when attacking mode 12500
so just try it for yourself and see whether or not your actual cracking speed of 20300 hashes is near your best benchmark for -m 12500
if yes, then yes, this is the best speed you can expect, if not, maybe your mask of length 6 is still "to short" for parallel work on your gpu
be aware most hashmodes with high iterations are considered to be slow