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Title: Interesting Load Observation Post by: phorensic on September 29, 2012, 09:17:22 PM I mine with 3 GPU's and mine LTC on my CPU. All 4 devices are overclocked to the edge of stability. After mining on the GPU's for about a year, and on the CPU for a couple months, I noticed something interesting albeit annoying. If I kill my mining programs, and thus reduce the load on my hardware to ~0, my computer will crash consistently in 5-15 minutes. I can reproduce this over and over. It's almost like I have conditioned the hardware and/or cooling solutions (possibly cooked the thermal interface material a certain way?) to only work under 100% load and high heat. It is also independent for the GPU's and the CPU, so for example if I just kill the LTC mining on the CPU I will crash in 5-15 minutes, and vice versa.
Anyone else have this phenomena happen to their hardware? Title: Re: Interesting Load Observation Post by: crazyates on September 30, 2012, 01:46:41 AM So you run both your GPUs (BTC) and your CPU (LTC) at 100%, and you have no stability issues.
You run just your GPUs (BTC), but no CPU, and your computer crashes. You run just your CPU (LTC), but no GPUS, and your computer crashes. You run neither, and your computer crashes. That is weird indeed! I wonder if it's a voltage thing. Maybe try a different PSU? Title: Re: Interesting Load Observation Post by: phorensic on September 30, 2012, 02:26:45 AM Yes, you got it right. Weird, right? My only guess so far, from 15 years of experience overclocking, watercooling, messing with HSF's and such is that when you run a device at 70-80C for long periods of time the TIM either changes its properties or gets so thin that it "squeezes" out slightly and when the chip cools and contracts it lets some sort of micro gaps form and you get hot spots which crashes the "chip". That is just a guess, though. Now that I think about it that doesn't make much sense because the only reason it should crash is if you see the die temp get too hot... Maybe I have worn the transistors out from all the heat/current and they only run right when there is full power flowing through them (or more specifically-full voltage, seeing as modern chips vary the voltage automatically with clock speed)? Here is an up to date article that explains what I learned a few years ago about how transistors wear out: http://spectrum.ieee.org/semiconductors/processors/transistor-aging/0 (http://spectrum.ieee.org/semiconductors/processors/transistor-aging/0)
I'm on my 3rd power supply. This one is an 80plus Gold OCZ 850W and I only pull about 550W. |