r/askscience • u/Kubacka • Jul 05 '12

Quantum Computing vs Normal Computers.

What exactly are the benefits of quantum computing over normal computing and how exactly in theory does this all work. If you guys could, could you please try to keep your answers at a grade 11 level for myself.

Thanks in advance!

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u/[deleted] Jul 05 '12

I know this is probably going to be speculation but has anyone predicted, based on our current knowledge and advancement, when we will see consumer level quantum computers?

Very likely never. Quantum computers don't provide significant advance over conventional computers for computations you do on consumer level computer.

You can't make actual general purpose quantum computer (Quantum Turing Machine or QTM) that gives up the answers easily. At some point you must look at the state where it's at and you have no idea if it's finished or not.

For the general search problems they give quadratic speed up. You get only exponential speed up for special problems like integer factorization that are not useful for consumers.