Overclocking versus Overvolting in Raspberry Pi. Which one is more dangerous ? Why ?

Discussion in 'Electrical | Electronics | Communications' started by Abhishek Rawal, Apr 29, 2014.

  1. Abhishek Rawal

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    I would like to know which parameter is more dangerous, OC'ing or OV'ing ?
    I would love to know reason behind the answer.
     
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  2. Jeffrey Samuel

    Engineering Discipline:
    Electronics
    I would say OV is more deadlier than OC

    Most transistor in any IC are not run at 100% of their effective speed. So OC ing will not destroy my chip.

    Whereas their voltage input tolerance is not upto the mark and their range of operation is limited. So OV can destroy the IC and doesn't allow the chip to work at all
     
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  3. Abhishek Rawal

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    Overvolting is not increasing Vin, we are not increasing juice flow while overvolting. Signal strength is altered to achieve overvolt, this is something on-chip. In my case, when I overvolt RPi to 6 or 8, that doesn't mean I am increasing Vin, RPi still operates at 5V.
     
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  4. Harshad Italiya

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    I have not much detailed information about Overvolting but I know if you are going to to do Overclocking it is going to consume more power and also going to produce more compare to slow clock.

    That is why if your device is battery powered try to keep clock as low as possible.
     
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  5. Abhishek Rawal

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    @Harshad Italiya I don't think that's correct. RPi devs have worked on Overclocking & Overvolting impact on lifetime of RPi and successfully added 1 GHz overclock option (known as Turbo mode) which can overclock your RPi without damaging it & w/o having any adverse impact on it. You can overclock from the four options available in 'raspi-config' under 'overclock' tab & the warranty won't be void.
    However, if you edit config.txt & edit custom parameters for OC'ing & OV'ing then the 'sticky bit' will set (1) and if you damage your RPi, the company will know that you overclocked to the parameters that weren't safe.

    I have already overclocked & overvolted my Raspi & I am pretty sure the sticky bit flag is set, because I use config.txt to set parameters. I don't care if my warranty is void, If I overclock to great extent, my RPi won't boot but there's nothing to worry as I can hold shift key & disable the overclock & turn all settings to default.

    Again, Overclocking or Overvolting, which is riskier ?
     
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  6. Void Runner

    Void Runner Enthusiast

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    Engineering Physics
    Overvolting = more heat, bandwidth effects. Causes metal migration phenomena and electrochemical corrosion over time. It also causes ionic displacement and exacerbates leakage currents (= more heat). On a whole overvolting will eventually destroy your chip. Overvolting also has an effect on internal resistances and capacitances of the material and device, and as such may change the V-I characteristics or region of operation away from the intended Q-point/region.

    Overclocking is generally a lot safer mainly because you are dealing mainly with heat effects only and not so much with corrosive phenomena. Thus, overclocking may mostly only cause chip problems at operation time, overvolting could even cause explosions (and irreversible damage) :D
     
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  7. Abhishek Rawal

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    #7
  8. Void Runner

    Void Runner Enthusiast

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    Engineering Physics
    ^The thread gives an overly simplistic definition of both overclocking and overvolting. The effects seen from overclocking are simply a result of the limitation on gain bandwidth product of any transistor based circuit on high frequency. By manipulating the signal such that a tolerance value is reached quicker (by raising the design limit), overvolting works to achieve something similar.

    The issue of why overvolting is bad is not explained very well in that thread. It is bad basically because it decreases the thermal, chemical and electrical efficiency of the carrier conduction process. Each time energy is not used efficiently, the remainder is converted to heat. That's why more volts = more heat. We then have electromigration and other chemical effects to consider.
     
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