I feel the answer to this question is just out of reach - I "understand" the implication that a quantum computer uses all combinations of bits simultaneously compared to a classic computer, and that clearly gives a huge boost to processing times, however I'm struggling to quite grasp how.
I watched a TED talk on quantum computing in which the gentleman said that a 300 qubit QC would be more powerful than a regular PC with one bit of memory for every atom in the universe. They also mentioned that Google have created a QC with 53 qubits.
So to try and get my head around it, I decided to compare this to my PC.
Forgetting memory needed for anything other than storing combinations, if I have 16GB of RAM available, that's 217'179'869'184 possible combinations, or ~57 million lots of 53 bits (with each one in one specific combination).
So for each cycle of combinations, my PC is able to hold ~57 million combinations of 53 bits, and if my PC is running at 4.1GHz, that's 7.0E+19, or in the region of 266 combinations per second.
Now I have a good PC, but it seems to be reasonably on a par with Google's quantum computer, which just seems wrong. I know that I've not used an exact science to calculate things but I can't follow where I've screwed up the maths?
The claim for the 300 qubit QC I also can't follow with the above logic.
As excel won't work with stupidly large numbers I tried to do this on paper, so bear with me:
There are 10E+80 atoms in the universe, so this number of bits would give 2(10E+80), or 2800 combinations. An unholy number that no-one could possibly comprehend.
For the QC there are 300 qubits or ~28 therefore one could store 2792 combinations at any one time, which is already way above the 2300 combinations available to a 300 qubit QC..?