hashcat Forum

Hi my AMD 7970 cooling isn't sufficient for running with stock settings, so I want to try throttle the card down so it doesn't overheat past 90 degrees.

I found the workload tuning options:
-n, --gpu-accel=NUM Workload tuning: 1, 8, 40, 80, 160
-u, --gpu-loops=NUM Workload fine-tuning: 8 - 1024

Right now I'm running
c:\ oclhashcat64 --hash-type 2500 --attack-mode 3 -u 1 -n 1
(Note: I suppose -u minimum is 8 even though I specified 1)
It is happily hashing away at 15k/sec.

While I know the card can do 140k/sec with good cooling, that is not an option. The case is open and ambient temp is ~70f.

I wanted to ask the community for is suggestions on how I should set my -u # and -n # settings to find a decent rate that doesn't overheat the card. What are the default tuning settings? I would like to try at 50% of the defaults and work my way up or down depending.

I tried searching but couldn't find a specific reference to this. Any help is greatly appreciated

You're kind of going about this the wrong way.

You shouldn't have any problems cooling a 7970. 70F ambient temp is irrelevant. Are you forcing the fan to 100% before starting a run?

If the fans are at 100%, then it sounds like you have an OEM design card, which, as has been explained on these forums multiple times, are designed for gaming workloads, and cannot cope with compute workloads.

If switching out the card for a reference design card is not an option, then your next option should be to underclock. Try bringing the core clock down to 850-900 Mhz and see where that leaves you.

Its not a great quality card (XFX) and I have had cooling issues. I recently re-applied thermal compound . I also did try forcing fan to 100% before starting but it still shoots up. I used this card to mine litecoins 24/7 back in the day and it would stay around 90c, albeit stable.

Can't seem to figure out how to underclock with the 14.9 drivers. I tried setting clock speed lower in AMD overdrive and it ignores and keeps it at 975. Tried evga precision and it wont let me go lower either.

I'd be happy even with 50k/sec if I could use the tuning options.

Definitely sounds like an OEM design card. Try lowering the mem clock along with the core clock.

As for workload tuning, you can try using -w 1

Don't know how your heat spreader is made, but it's possible in same way as 6990 (heatpipe on the crystal), so you just could damage it by pressing too hard when cleaning.

-w 1 is working well getting 42k and temp 83

this will speed up my hash time considerably. I started cpu hashing getting 5k and the ETA was 22 days. Then found hashcat and its only going to take ~3 days to exhaust the keyspace now.

Thanks for the help!