# RAM and the degrees of freedom

This question is about computation/computational physics.

Imagine that you want to solve $10^6$ equations of motion, and you have $10^6$ degrees of freedom (position of the particle).

How many RAM memory would you need (theoretically) to do this?

(I am not interested in the final answer, I am just interested in the thinking of estimate this.)

Thank you

• I would imagine you would need to store $10^6$ floating point numbers. A double uses up 8 bytes, so you would need around 8MBs. – Yuval Filmus Aug 28 '17 at 18:01
• This probably highly depends on the type of the equations, and how you intend to solve them – Ariel Aug 28 '17 at 22:19
• This might be a better fit for Computational Science but it seems off-topic here, to me. – David Richerby Feb 28 '18 at 18:43

As a first approximation, most of the memory will be spent on storing $10^6$ floating point numbers (one per degree of freedom). Assuming double precision numbers are used, each number takes up 8 bytes, for a total of 8MB.