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One GPU fan reads (-1%) and overheats. How can I fix this? - Printable Version

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One GPU fan reads (-1%) and overheats. How can I fix this? - Sleet - 07-18-2014

Just like the title says. I saw the post where someone had the audacity to talk about a way he thought hashcat could be beat (he was wrong) but all the big hitters on this forum came running to tell him just how wrong he was. I had posted just before him and only got someone telling me I run my cards too hot and zero mention of one fan shutting down.

Could I get help with this please? This is an amazing program and I would like to get the most out of it but one GPU isn't cutting it.


RE: One GPU fan reads (-1%) and overheats. How can I fix this? - epixoip - 07-18-2014

fanspeed is likely reading -1% because you don't have a gpu fan. this is very common in laptops/notebooks where the cpu and gpu merely have heat pipes running to a shared heatsink with one or two system fans.


RE: One GPU fan reads (-1%) and overheats. How can I fix this? - Sleet - 07-18-2014

(07-18-2014, 07:50 AM)epixoip Wrote: fanspeed is likely reading -1% because you don't have a gpu fan. this is very common in laptops/notebooks where the cpu and gpu merely have heat pipes running to a shared heatsink with one or two system fans.

Ok great! Thank you very much for answering me! I'm pretty sure my model has two fans but I will double check

Edit - Just checked it out again and it does have two. I know I can hear/feel it while gaming or when I run a diagnostic test on it. I'll tear it apart tomorrow and see if I can see something wrong with it anyways. Here is a video showing both fans.

https://www.youtube.com/watch?v=j20wn96uac0#t=408


RE: One GPU fan reads (-1%) and overheats. How can I fix this? - epixoip - 07-18-2014

from what i can tell in that video and a couple other videos i watched of people tearing down the same model, those fans don't plug into the GPUs, they plug into the mainboard. so they appear to be system fans that the GPUs tap into via a heat pipe.

it's entirely possible that the GPU driver does not know about those fans, or cannot control those fans, or can only control one of the fans, or can only see some common controller on one GPUs that actually controls both fans simultaneously. laptops are a bit complicated in that the oems pretty much have free reign over the design, and do all sorts of things that the chipset manufacturers may not have accounted for, so nothing is really out of the realm of possibility here. you would need to really dig into the low-level specifics of your laptop to find out what's going on.

the important thing to note here though is that hashcat doesn't actually control your fan speed, that is purely there for reference. you need to use some other utility to actually control the fan speed.

another important takeaway is that the cooling solutions in laptops are absolutely not made to cope with the electrical draw and heat generated by compute workloads. running hashcat on a laptop for any extended period of time is a sure-fire way to ensure the untimely death of your system.


RE: One GPU fan reads (-1%) and overheats. How can I fix this? - Sleet - 07-19-2014

Thank you so much epixoip. This is the kind of information I have been searching for. You covered things I wouldn't even have thought to look at. I am rather fond of my laptop and am in no hurry to put it in its grave. I will now turn my focus towards maybe building a desktop. I do have one question about that though. Can a great cracking machine also be a great gaming computer? I would rather not drop 2 grand on GPUs if the system is only good for one thing.


RE: One GPU fan reads (-1%) and overheats. How can I fix this? - epixoip - 07-19-2014

i don't play computer games, but i'm pretty sure the Radeon R9 line is pretty decent for gaming. i know most gamers prefer Nvidia though.

i suppose it depends on which you'll be doing more. if you primarily play games and only occasionally crack hashes, then go with some top-of-the-line Nvidia GPUs. the performance-per-dollar won't be there for hash cracking, but it will still be decently fast compared to what you are using now. if you want oustanding hash cracking performance and good (but maybe not the best) gaming performance, then the 290X is probably your best bet.


RE: One GPU fan reads (-1%) and overheats. How can I fix this? - Mangix - 07-22-2014

Or wait for higher end Maxwell GPUs.