07-03-2013, 06:07 AM

(06-27-2013, 03:47 AM)JohnnyYesterday Wrote: Those appear to be talking about irreversible computation, so their figures aren't applicable here since reversible computation is thermodynamically reversible.

That's why it is so efficient, and doesn't turn into a hot plasma from its own waste heat.

Sigh. For the nth time, reversible computing isn't a free lunch. TAANSTAAFL.

Reversible computing was rehashed here:

http://movies.groups.yahoo.com/group/ori...sage/54610

Which, if you don't have access to the archives, is:

On 3/15/06, drashner1 <drashner1@yahoo.com> wrote:

> > > a) What about reversible computing? One of my books talks about

> >

> > I've been unable to wrap my mind around it.

>

> Same here. And this bothers me since it gives me this vague feeling

> that we could be missing something here.

Erm, not really much to say about reversible computing.

For an N-step algorithm, which normally expends energy ~ kTN using an

irreversible process, you may reduce the energy use by a factor of N^b

(0<=b<=1), but then the calculation will take a factor of N^b longer.

It just means an archai can throttle down their power use by slowing

their thinking.

No free lunches here. The same total energy is still expended. (And it

would be quite startling if that weren't the case.)

> Todd

>

> > -xx- Damien X-)

Adam

--

"Invincibility is in oneself, vulnerability in the opponent." -- Sun Tzu