Spiking CPU/GPU ussage for 7z
#1
I have a 7z archive I made a while back. I saved the password using keepass but lost the keepass file. I know the rules I used to generate the password so I've (To the best of my ability, pretty new at this) set up hashcat to crack the password. The problem is that hashcat is constantly saying that my gpu has hit the threshold temperature, despite it hovering at around 70-80 deg C. Also, my GPU and cpu usage isn't consistently high like I expect. They spike up to 100% for half a second, then back down to idle. They do this constantly. I have an AMD 5800X and Nvidia 3090, and I can only do about 4700 H/s. I don't know if that's a lot or not since I can't find any comparisons online, but I know it's not as high as it could be since it's not fully using my GPU. Any tips?


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#2
If you're hitting 70-80C you should probably consider turning your fans up or making better airflow. I know that theres the rule of thumb that GPU's are capable of 90C comfortable but that is strictly the CORE temperature, does not mean other components are not getting hotter. 3090's are terrible at maintaining temperatures because the memory chips are on both side of the PCB and only passively cooled by the backplate. So, you could be running into thermal throttling and see those spikes. The other thing is you are using task manager, which in course does not properly show usage correctly for hashcat.

I would suggest improving your cooling solutions and bringing the temps to a more stable position and disable any overlocks. Once you have done that you may see more consistent hashrate.

As for the hashrate, 7z has an iteration count applied to it during encryption so the higher the iteration the harder it will be to crack/slower the hash speed will be. So finding a benchmark of say 40,000H/s might not be comparable since it has an iteration of 1000 where you might have an iteration count of 10000 and only getting 4700H/s if that makes sense to you.
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#3
I don't think it's temperature. I set the fans to 100% and turned on the AC (Positioned above the computer). Ran the test again, still peaking and dipping like before, highest peak temperature is 70 C, average peak temperature 68 C. I don't see a way to post another picture, but if I find it I can upload again.

As for task manager, I'm seeing the exact same results in process explorer.

The 7z hashrate makes sense. I love secure encryption until it bites me in the butt!
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#4
I was originally running Nvidia 531.29, Just updated to 531.79.
After the update I'm now getting ~5000 H/s which is faster, and it looks like there is less gpu power being utilized so a win win. Still very low GPU temperatures and complaints about overheating, and still spiking CPU and GPU usage.
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