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Old 2017-06-29, 20:35   #26
CRGreathouse's Avatar
Aug 2006

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Originally Posted by manasi View Post
Well, I know less about - GMP if you mean to say GMP has no restriction on space. I have been talking about working with very large numbers.
There are a number of different limitations to consider.

First are architectural limitations. I'm not sure what it is for GMP but for example in PARI/GP you can have t_REAL numbers up to almost 2^2^29 on 32-bit systems and 2^2^61 on 64-bit systems.

Next there are memory limitations. If you want to store 2^10^15 directly you need 10^15 bits of memory. On 64-bit systems this is more likely to cause trouble than architectural limitations.

Finally there are practical limitations imposed by the algorithms used. If you want to factor the numbers, it doesn't matter if you could store billions of digits because you won't live long enough for a current computer running current software to factor such a beast.
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