title: What Exactly Happens When Python 64-bit Runs Out of Memory?
body: <p>recently I had to use a list of a large number of lists for a program. I tried to make a large list of lists, by running <code>list= [[] for _ in range(200000000)] </code> on the command line, and I opened Task Manager. Firstly, Python started using up more and more RAM, until it ate up 10GB out of my 11.9GB of RAM. Then, I saw a dip in the usage of RAM on python to about 3000MB, and the Task Manager showed that python started using Disk. Does that mean that python 64-bit starts saving variables in the hard drive when it doesn't have enough RAM left?</p>
  <p>If so, is there a way to do it manually, and how fast is it? (a bit of a relative question, I expect an answer like &quot;it takes 30 times more to lookup from SSD than from RAM&quot;, and, &quot;Python can transfer 30MB/s from RAM to a Hard Drive, or store variables in a Hard Drive without using RAM&quot;).</p>
  <p>P.S. I got an SSD.</p>