I don't think this should be possible. Perhaps your computer is broken. If you can reproduce the problem with an input file of a mere 100kB, [here's a different computer for you](https://bellard.org/jslinux/). (Console output is pretty slow, there's only a few megabytes of free space as well). The output from running your program under `time` will not match real seconds for some reason. The clipboard text box doesn't accept keyboard input for me (Firefox 53), so I used the right-click menu to copy data in through `/dev/clipboard` as per the FAQ. I might try running `debsums` or `rpm --verify -a` in this case. Previously I've had weird behaviour caused by silent disk corruption.