There are tons of guides out there on how to “tune” most anything. With alarming frequency, I find things in them that are flat-out wrong, or, at the least, accomplish nothing productive. A classic example is the advice on emptying your Prefetch folder on Windows to make it go further. If you read up on what the Prefetch folder is, or read interviews with any of the core Windows team pulling their hair out about how many people keep deleting it, you won’t be able to help but laugh next time you see someone recommending it: until you realize that most Windows tuning guides recommend that. There was also a classic one on allowing SMP support during boot, which Microsoft announced in short order actaully did nothing: it was already using multiple cores if they were there. I still see that recommended a bit.

I was Googling an arcane option in Linux’s sysctl.conf file, and came across a lot of guides on how to tweak sysctl.conf. Very few go into any detail; they just list settings they think you should use. So you’re left blindly changing things that you probably shouldn’t change, like low-level TCP options, because some random website on the Internet said it would make Linux faster.

There’s plenty of good tuning to be done, but there’s also plenty of really bad advice out there. And a plea to others writing tutorials: if you’re going to show people how to change values, can you give some explanation of what they mean? “Controls the use of TCP syncookies” above “net.ipv4.tcp_syncookies=1” is not a helpful comment. Yes, I know what SYN cookies are, but that comment doesn’t convey any information.

I did find a helpful ipsysctl tutorial that goes into detail about what each one does, as opposed to recommending values with no explanation.