# Why are computers so reliable?

In any complicated system, there is always some scope for error. When I program on my computer, the system computes perfectly each time. 1+1 always turns out to be 2. We take reliability of the computer almost for granted. What gives modern computers it's reliability? Are there no errors in computation, or errors, if any, are corrected by some means?

• – Juho Nov 4 '14 at 9:25
• I think the premise is flawed. It's not that computers are perfect, it's just that errors are so rare that nobody bothers to account for them. If you run 1+1 often enough, you may observe errors. As a fun exercise, take an off-the-shelf PC to outer space and count errors then. (Hurry, your machine may not compute anything for long at all.) – Raphael Nov 4 '14 at 10:50
• What gives modern computers it's reliability? Modern technologies and engineering approaches that are used to build these computers. By the way in your example of 1+1 you are using a relatively simple part of the whole complicated system so its chances of reliability are higher as compared to other tasks which access all of complicated parts of the system. – Ankur Nov 4 '14 at 11:19
• I wonder: should we move this question to Electrical Engineering? – Raphael Nov 4 '14 at 16:35