Whenever I want to download something which is over a gigabyte, I leave my computer, so the download could happen smooth and fast, but that's not to be, when my computer goes to sleep, and the Wi-Fi turns off.
In OS X 10.8 Apple introduced an "aggressive system sleep" to aid laptop power consumption and battery life. This means that applications have to tell the OS when they don't want it to sleep because they are, say, working on a long task that doesn't require user input.
If you're using an application that hasn't been updated to issue these requests (known as power assertions) you can issue them yourself from the command line using the
The machine will stay awake until you abort the command with CTL+c. To allow the screen to sleep as per your normal System Settings use,
To make the power assertion expire after a fixed number of seconds (e.g., 1 hour = 3600 seconds) use,
Once that expires your normal sleep settings will resume.
When your mac goes into sleep mode, your hardware will goes to sleep mode. Hence, it is not possible for you to keep your wifi on while in sleep mode.
To workaround, you may: