Regarding Configuration files

Hi All, I need to take a design level decission in using configuration files and request to provide your inputs on this.

My product is having a single configuration file covering the basic configurations. While using this for a project the no of lines in this configuration file is exceeding 4000 lines.

So my developers comming back and suggesting to have this configuration file to be splitted into mutiple.

But my concern here is that if we split the configuration files, it will be difficult in handling mutiple files and tracking on what configuration goes into which of configuration files will be very difficult

Also to my view its better to have a single configuration file as this file gets loaded only once into memory and that way increase performance when compared with using many configuration files.

Request to provide your thoughts on the same.

Thanks,
Sreedhar