Is 1 more expensive than 0?

By: Michael S (, November 21, 2022 10:51 am
Room: Moderated Discussions
Foyle ( on November 21, 2022 7:58 am wrote:
> Andrey ( on November 21, 2022 4:23 am wrote:
> > This will probably be a naive and silly question, but I'm curious.
> >
> > Assuming that a logical one is represented with a higher voltage than a logical zero in the IC,
> > is it fair to say that ones are more expensive to process in terms of power and heat? That is,
> > if it takes more energy to charge a DRAM or SRAM cell to a level of one (in case of DRAM - also
> > to refresh it), if it takes more voltage to transfer the signal along the traces, if this voltage
> > makes more heat in the transistors implementing a logical circuit within the IC, thus causing
> > more leakage current, wouldn't it be more expensive? I wonder if someone tested this.
> >
> > If there is a measurable difference, wouldn't it make sense to account for that when designing the ICs and
> > writing software? On the hardware level, it might make sense
> > to process negated signals or a mixture of positive
> > and negated signals to reduce the number of "ones" or at least make them statistically closer to "zeros" so
> > to reduce the possible power consumption spikes. In software,
> > it would make sense to prefer zero or power-of-two
> > representations of data more often. Of course, it is not
> > possible to have a useful machine (both in hardware
> > and software) processing only zeros, but some difference could be made. Or could it?
> >
> I don't know about computation, but this has long been recognized and designed for in data transmission. For
> example memory buses since GDDR4 use DBI (data bus inversion) to minimize the number of energy-expensive
> line states, and apparently some buses use inversion encoding to minimize the number of transitions.

Minimizing # of transitions - that far I understand.
But preference for transmission of zeros over transmission of ones or vise versa?
It made sense on old Intel's AGTL+ buses that were terminated asymmetrically.
DDR buses are terminated symmetrically toward the middle level, so I fail to see how zero is better (or worse) than one.
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TopicPosted ByDate
Is 1 more expensive than 0?Andrey2022/11/21 05:23 AM
  Is 1 more expensive than 0?Juha Lainema2022/11/21 06:15 AM
  Is 1 more expensive than 0?Adrian2022/11/21 07:21 AM
    Is 1 more expensive than 0?anon22022/11/21 05:29 PM
  switching between 0 and 1 is what consumes powerHeikki Kultala2022/11/21 07:23 AM
    Thank you all for your answers. (NT)Andrey2022/11/21 08:29 AM
  Is 1 more expensive than 0?Foyle2022/11/21 08:58 AM
    Is 1 more expensive than 0?Michael S2022/11/21 10:51 AM
    Is 1 more expensive than 0?Captain Obvious2022/11/21 11:29 AM
      obvious stuffanonymou52022/11/21 02:25 PM
        obvious stuffAndrey2022/11/21 02:50 PM
          obvious stuffMichael S2022/11/21 03:43 PM
  SRAM is bistableAnon2022/11/21 10:50 AM
    SRAM is bistableAndrew Clough2022/11/22 05:53 AM
  NAND Flash 1 and 0jokerman2022/11/24 01:13 PM
    NAND Flash 1 and 0Joern Engel2022/11/25 12:00 AM
      NAND Flash 1 and 0Ungo2022/11/25 02:26 AM
        The ECC needs to be stored. as ones ane zeroes (NT)Heikki Kultala2022/11/25 08:31 AM
          The ECC needs to be stored. as ones ane zeroesanon22022/11/25 05:07 PM
            The ECC needs to be stored. as ones ane zeroesHeikki Kultala2022/11/26 12:48 AM
              The ECC needs to be stored. as ones ane zeroesanon22022/11/26 02:00 AM
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