Hashcat Brain Service

[hashcat-study]

How to ensure 100% utilization of GPU in brain server

Running code using brain services

hashcat -O --brain-client --brain-client-features=2 --brain-host=172.16.100.198 --brain-port=996110 --brain-password=BRAIN -a 3 -m 0 'df96220fa161767c5cbb95567855c86b' --status --status-timer 3

The utilization of GPU is as follows

Hardware.Mon.#2..: Temp: 43c Fan: 28% Util:  0% Core:1544MHz Mem:3802MHz Bus:16
Hardware.Mon.#3..: Temp: 46c Fan: 30% Util:  0% Core:1544MHz Mem:3802MHz Bus:16
Hardware.Mon.#4..: Temp: 42c Fan: 28% Util:  0% Core:1506MHz Mem:3802MHz Bus:16
Hardware.Mon.#5..: Temp: 42c Fan: 28% Util:  0% Core:1506MHz Mem:3802MHz Bus:16

Hardware.Mon.#2..: Temp: 44c Fan: 28% Util:  0% Core:1746MHz Mem:3802MHz Bus:16
Hardware.Mon.#3..: Temp: 47c Fan: 30% Util: 42% Core:1733MHz Mem:3802MHz Bus:16
Hardware.Mon.#4..: Temp: 43c Fan: 27% Util:  0% Core:1594MHz Mem:3802MHz Bus:16
Hardware.Mon.#5..: Temp: 43c Fan: 27% Util:  0% Core:1645MHz Mem:3802MHz Bus:16

Hardware.Mon.#2..: Temp: 45c Fan: 28% Util: 62% Core:1860MHz Mem:3802MHz Bus:16
Hardware.Mon.#3..: Temp: 48c Fan: 30% Util:  0% Core:1911MHz Mem:3802MHz Bus:16
Hardware.Mon.#4..: Temp: 43c Fan: 28% Util:  0% Core:1594MHz Mem:3802MHz Bus:16
Hardware.Mon.#5..: Temp: 43c Fan: 27% Util: 25% Core:1645MHz Mem:3802MHz Bus:16


No use of brain services

hashcat -O -a 3 -m 0 'df96220fa161767c5cbb95567855c86b' --status --status-timer 3 

Hardware.Mon.#2..: Temp: 48c Fan: 29% Util: 74% Core:1721MHz Mem:3802MHz Bus:16
Hardware.Mon.#3..: Temp: 51c Fan: 31% Util: 70% Core:1645MHz Mem:3802MHz Bus:16
Hardware.Mon.#4..: Temp: 47c Fan: 28% Util: 39% Core:1721MHz Mem:3802MHz Bus:16
Hardware.Mon.#5..: Temp: 45c Fan: 28% Util: 83% Core:1784MHz Mem:3802MHz Bus:16

Hardware.Mon.#2..: Temp: 52c Fan: 29% Util: 94% Core:1771MHz Mem:3802MHz Bus:16
Hardware.Mon.#3..: Temp: 57c Fan: 31% Util: 92% Core:1822MHz Mem:3802MHz Bus:16
Hardware.Mon.#4..: Temp: 51c Fan: 28% Util: 84% Core:1873MHz Mem:3802MHz Bus:16
Hardware.Mon.#5..: Temp: 51c Fan: 28% Util: 92% Core:1809MHz Mem:3802MHz Bus:16

Hardware.Mon.#2..: Temp: 54c Fan: 30% Util: 93% Core:1771MHz Mem:3802MHz Bus:16
Hardware.Mon.#3..: Temp: 59c Fan: 33% Util: 94% Core:1822MHz Mem:3802MHz Bus:16
Hardware.Mon.#4..: Temp: 53c Fan: 30% Util: 94% Core:1835MHz Mem:3802MHz Bus:16
Hardware.Mon.#5..: Temp: 53c Fan: 29% Util: 93% Core:1809MHz Mem:3802MHz Bus:16

[philsmd]

brain is most useful for so-called slow hashes ,therefore try with e.g. -m 3200 = bcrypt , sha256crypt, PBKDF2 etc

It's always a question on where the bottleneck is, if hashcat is too fast for the server, it's probably not a good idea to use brain if the server/connection is the bottleneck.

The main goal of brain is to avoid redundant work for slow hashes. therefore -m 0 is not a good choice to test/run

[hashcat-study]

Ok, my current understanding is that the task issued by the brain server is too fast, so the gpu is useless. The task of slow hash is relatively heavy.

[philsmd]

maybe you are confusing the brain feature with some distributed cracking software like hashtopolis.

They address very different problems, but still some users think that the brain feature is some software to distributed work, while it is not.