When is a .php file too large? [closed]

Question

I'm writing a PHP class. At the moment there are 1,000 lines of code and the file size is 46 KB. It's not an insane size, but this got me to thinking.

Q: At what point would performance start to be affected due to file size and/or the amount of code included in the PHP file?

Answer 1

For php there is no noticeable difference (especially if you use any opcode cache) if there is 10 files each 100 lines or 1 with 1000 lines.

But from maintainability point of view it would be better to split the class responsibilities to several.