The MAC OS is based on Linux and normally loads web pages as fast or faster than a comparable Windows system. In an system it will depend on the browser, processors, available memory and the stability of your network connection to access the internet. If you don't feel the CPU or memory are issues you can check the network performance with mtr (or WINMTR) which combines ping and trace route commands to check connection performance and packet loss.
It might be due to DNS prefetching problem.
There are 2 options to solve this problem.
1. Change your DNS service
2. Disable the DNS prefetching
If disabling the DNS prefetching, solve your issue, then main problem lie within your router.
try type in a terminal code to speed up you wifi. google the code then enter it correctly, if its with caps-lock then do it. if u enter it wrong it wont work. that is a easy way to speed your wifi speed up. u can find terminal by using finder, it should be in the apps category