I tell you that how to speed up your downloading speed using idm.
So be careful and follow the steps given below:

Open your Internet Download Manager (IDM).
Click on the downloads option and then click on connections.
Select the option of 16 for Default max options.

Then click OK. Now click on Download again and then click the settings and set the maximum speed of 1024 and click down on always turn on

Now check your download speed Thanx
Admin