3 ms·
Reversible computation is inherently slow computation and the main advantage is it lets you get below this limit but current computers are still many (dozens?)
by tgb 9y ago
Reversible computation is inherently slow computation and the main advantage is it lets you get below this limit but current computers are still many (dozens?) of orders of magnitude off from reaching that limit. Until then, you'd be better off just improving efficiency of non-reversible computers.
- abecedarius 9y agoThat wiki page says "Although the Landauer limit was millions of times below the energy consumption of computers in the 2000s and thousands of times less in the 2010s,[3] proponents of reversible computing argue that this can be attributed largely to architectural overheads which effectively magnify the impact of Landauer's limit in practical circuit designs, so that it may prove difficult for practical technology to progress very far beyond current levels of energy efficiency if reversible computing principles are not used.[4]" On a skim it looks like [4]'s argument is that people have been criticizing the overhead of fully reversible circuits, but only 'conditionally reversible' circuits are needed for the power benefits.
- tgb 9y agoWow have we improved that much in efficiency? I learned about this from the Feynman lectures on computing which are perhaps a little out of date.
- tgb 9y agoAdding: I looked it up and Feynman quotes 10^8 times as much energy dissipated per step as the Van Neumann-Landauer limit when using the transistors of his era (1984-86 is when he taught the course).
- GTP 9y agoBased on this statement there is also another possible way: remove the architectural overheads that magnify the impact of Launder's limit. So probably he is right saying that there are other improvements that are easier to accomplish that we can do before caring about Launder's limit.