Smart Pause/Smart Start (Suspend downloads / Start suspended ) [Shift+Ctrl+P]
It stops all downloads but remembers their state or starts all stoped downloaded restoring their state.

Now
Start or stop download right now.

If inactive
Downloads are started if the computer has not been used for more than 20 minutes.

In
Downloads will start in the specified time.

( i ) This option is convenient if current downloads interfere with other programs which use Internet connection. You can stop the downloads and they will start again automaticaly according to the chosen mode, for example, after you finish working with the computer.

Speed

Maximum
Use maximum speed while downloading files.

Medium
Use medium speed while downloading files. Allows you to download files and surf the Web.

Low
Use low speed while downloading files. It's a very useful if you have enough time for your downloads or you are using the Internet actively.

Automatic
In this mode download speed will be set low while any of the specified programs is working with network (for Windows versions prior to XP this feature works only for Internet Explorer). It is intented for comfortable netsurfing while IDA maintains maximum download speed.

Manual
While you are working in this mode you may correct your download speed using the toddler in the status panel.

( i ) In "Options" -> Connection" You may change the maximum download speed and number of threads per download.