iOS and macOS™ Performance Tuning: Cocoa®, Cocoa Touch®, Objective-C®, and Swift™

12. I/O: Pitfalls and Techniques

Despite the fact that I/O performance has increased more slowly than the improvements in other parts of the system, it still is fast enough for low-rate or reasonably small I/O...in computer terms. In human terms, that is still incredibly fast. For example, the Project Gutenberg version of a reasonably large novel such as Moby Dick is just 1.2 MB in size. On my SSD-equipped MacBook Pro, I can copy this file 280 times per second using a shell script. The fastest typist in the world, on the other hand, types less than 20 characters per second, so in case we were working on our Moby Dick-sized novel, we would be able to save the entire novel on every keystroke and have plenty of time left for other tasks. For many ...