1.Type about:config in the address bar and hit return then look for the following ....

network.http.pipelining
network.http.proxy.pipelining
network.http.pipelining.maxrequests

When you enable pipelining it will make several request at once, which really speeds up page loading.

2. Alter the entries as follows:

Set network.http.pipelining to true

Set network.http.proxy.pipelining to true

Set network.http.pipelining.maxrequests to some number like 30.It will make 30 requests at once.

3. Lastly right-click anywhere and select New-> Integer. Name it nglayout.initialpaint.delay and set its value to 0 (zero).