Click on the Apple Logo and open up System Preferences.
Find the Network icon and click on it.
After this, if you're connected via Ethernet or Wi-Fi, click on Advanced in the bottom right.
Click on the DNS tab. You will now be able to enter DNS servers, if there are any DNS server inside of the box, delete them. There will be something in there but it should be greyed out before you enter the new DNS servers. Click on the Add (+) button in the bottom left hand corner. Type in the following DNS servers for US/UK: Preferred DNS Server: 220.127.116.11 Alternate DNS Server: 18.104.22.168 Type in the following DNS servers for Asia: Preferred DNS Server: 22.214.171.124 Alternate DNS Server: 126.96.36.199 If these don't make it any faster, please go here (scroll down to find your country) and check the best DNS servers for your country.
Click OK and you should be good to go!