My website is programmed in PHP and currently uses HTTP compression (gzip) using PHP's built-in compression functions. (I cannot use mod_deflate.c because my shared hosting provider will not install it because it would use a lot of CPU.) The shared server where my website is hosted currently hosts 100 other websites. I have programmed the html and css quite efficiently and there is not much room to rewrite the same thing with less markup. My images are already compressed.
My question is whether using PHP's compression actually is faster for the user than sending it uncompressed.
1. The CPU compresses the output, sends the output to the browser and the browser has to decompress it. (Compression functions use considerable CPU on both computers.)
2. Send the output uncompressed. (Saves CPU but sends more data.)
Is it worth it to compress my webpages if each consist of 20kb of html/css and 30kb of images?