09-06-2015, 06:45 PM
(This post was last modified: 09-07-2015, 12:02 AM by rico.
Edit Reason: cudaHashcat scores added
)
I was wondering about this myself. I was playing with NTLM (-m 1000) a couple of nights ago and noticed that prepending even a single character slows the hash rate to ~25% whilst append works the same, e.g.
Straight mask = 13,500 MH/s:
Prepend a character (replace first ?l) = 3,400 MH/s:
Append append a digit (replace last ?d) = 13,586 MH/s:
For reference, this same card benches at 16877.9 MH/s. Yes, I know about tweaking -n and -u but the issue remains either way.
EDIT: cudaHashcat64 does the same thing on a GTX 760 (3607.4 MH/s vs 1020.4 MH/s = ~28% performance).
Straight mask = 13,500 MH/s:
Quote:oclHashcat64 -m 1000 -a 3 hash.txt ?l?l?l?l?l?d?d?d?d?d?d?d
oclHashcat v1.37 starting...
Device #1: Cypress, 1024MB, 735Mhz, 20MCU
Device #2: Cypress, 1024MB, 735Mhz, 20MCU
Hash.Type......: NTLMSpeed.
GPU.#1...: 6735.8 MH/s
Speed.GPU.#2...: 6772.5 MH/s
Speed.GPU.#*...: 13508.3 MH/s
Prepend a character (replace first ?l) = 3,400 MH/s:
Quote:oclHashcat64 -m 1000 -a 3 hash.txt n?l?l?l?l?d?d?d?d?d?d?d
Hash.Type......: NTLM
Speed.GPU.#1...: 1691.8 MH/s
Speed.GPU.#2...: 1725.2 MH/s
Speed.GPU.#*...: 3417.0 MH/s
Append append a digit (replace last ?d) = 13,586 MH/s:
Quote:oclhashcat64 -m 1000 -a 3 hash.txt ?l?l?l?l?l?d?d?d?d?d?d7
Hash.Type......: NTLM
Speed.GPU.#1...: 6771.4 MH/s
Speed.GPU.#2...: 6815.0 MH/s
Speed.GPU.#*...: 13586.3 MH/s
For reference, this same card benches at 16877.9 MH/s. Yes, I know about tweaking -n and -u but the issue remains either way.
EDIT: cudaHashcat64 does the same thing on a GTX 760 (3607.4 MH/s vs 1020.4 MH/s = ~28% performance).