Internet Download Manager is one of the best download managers. According to its developer, IDM can increase your download speed by five times! However, if for some reason you still need an even higher download speed, then there is the possibility to increase the file transfer speed by adjusting the configuration in the software to optimize your internet bandwidth.
Steps

Step 1. Check your IDM connection parameters
If you are using a broadband connection, then select the high bandwidth connection type in the Options> Connection dialog box.

Step 2. Increase Default max
conn. number.). Open the IDMan.exe file, go to the Options tab, click on the Connection link and change the Default max. Conn. Number. Value from 8 to 16. Click "OK".

Step 3. Disable the Speed Limiter
Open the IDMan.exe file, go to the Download Menu from the menu bar, go to the Speed Limiter tab and select the Turn off option.

Step 4. Free up space
Just remove other downloaded items from IDM and reduce the number of downloads in the program queue.

Step 5. Close other applications
They can download something at the same time. It is better to close these applications as they also consume the Internet. Closing applications on a PC, for example, will allow IDM to use all of your RAM.

Step 6. Schedule your downloads
Due to the significant reduction in Internet traffic, downloads will go much faster at night.
Advice
- Try to download from the site mirror.
- You can also check with your ISP about bandwidth limits and download speeds.