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+--- Thread: Speed reduction (/thread-4734.html)
Speed reduction - ankur - 10-13-2015
Input.Mode.....: Mask (?d?d?d?d?d?d?d?d?d?d?d?d?d111) [16]
Speed.GPU.#1...: 2877.0 MH/s
Input.Mode.....: Mask (111?d?d?d?d?d?d?d?d?d?d?d?d?d) [16]
Speed.GPU.#1...: 611.1 MH/s
RE: Speed reduction - epixoip - 10-13-2015
Left half of the mask is too small to gain any acceleration. Learn how the program works.
RE: Speed reduction - ankur - 10-13-2015
Input.Mode.....: Mask (1?d?d?d?d?d?d?d?d?d?d?d?d?d?d?d) [16]
Speed.GPU.#1...: 2915.3 MH/s
RE: Speed reduction - ankur - 10-13-2015
Why does speed reduces so much when the mask is 111?d?d?d?d?d?d?d?d?d?d?d?d?d ?
RE: Speed reduction - epixoip - 10-14-2015
Because the left mask keyspace is too small and therefore you're not giving the GPU enough work to do.
RE: Speed reduction - atom - 10-14-2015
What epixoip means is the following, take the first 4 chars:
Quote:Input.Mode.....: Mask (?d?d?d?d?d?d?d?d?d?d?d?d?d111) [16]
?d?d?d?d = 10 * 10 * 10 * 10 = 10000
Quote:Input.Mode.....: Mask (111?d?d?d?d?d?d?d?d?d?d?d?d?d) [16]
?d?d?d?d = 1 * 1 * 1 * 10 = 10
What oclHashcat ideally needs, is a number > 256 to archieve full speed. There's no way to "fix" this because it's not a bug. For detailed information why it's not possible to change this read this: https://hashcat.net/events/p13/js-ocohaaaa.pdf page 23.
There's however a way to solve this for your special use case by using a salted variant of your hash. For example in case you try to crack sha1, take -m 120 and generate a file:
Quote:b89eaac7e61417341b710b727768294d0e6a277b:111
And then instead of using the mask:
111?d?d?d?d?d?d?d?d?d?d?d?d?d
use:
?d?d?d?d?d?d?d?d?d?d?d?d?d