There are a number of ways to boost/increase download speed in IDM .
METHOD ONE
This method opens all the segments in the IDM software hence increasing it's speed
- Download IDM OPTIMIZER from HERE
- Open your Internet Download Manager and start downloading... You could also just open it without starting download.
- Now open IDM OPTIMIZER and click on Maximize now
Restart IDM and enjoy the opened links it now provides
METHOD TWO
This is a manual method for the above
- Go to Downloads on the tool bar
- Speed limiter >>> Options >>> connections
- change "Default max. con. num " to 16 and click on ok the save
Enjoy full connection segments in IDM
DOWNOAD IDM free forever here