One of the main benefits of Amazon’s Fire TV Edition television, over a Fire TV or Fire TV Stick, is the built-in TV tuner. With it you have access to free over-the-air channels right from the Fire TV interface. While watching live TV, the Fire TV Edition television automatically records what you’re watching so that you can pause live TV and rewind at will. By default, the television will only record 5 minutes of live TV, but if you insert an SD card into the device, the operating system will use the available storage on the card to record live TV for much longer.

While watching an OTA channel on a Fire TV Edition television, it automatically records what you’re watching. This allows you to pause live TV and resume watching at your leisure. It also allows you to rewind live TV if you missed something. It’s a great feature, which is why it was disappointing to find that it only stores about 5 minutes of live TV. So if you pause the live broadcast, it will automatically unpause after 5 minutes. It also means you can only rewind a maximum of 5 minutes.

Thankfully, if you have an SD card inserted into the televisions SD card slot, the TV will use the available free storage on the card to extend its recording limit. With an SD card inserted, I was able to pause live TV for over an hour without any issues. The television happily continued recording onto the SD card and allowed me to move forward and back to any point in that 1+ hour-long recording.

With an SD card present, I don’t know if there is a limit to how much the TV will record because I haven’t yet paused or watched a single channel for much more than an hour yet. It seems as though as long as there is free space on the SD card, the Fire TV Edition television will continue to record until it runs out of space.

Looking at the available storage space of the SD card while I had a live channel paused, it seems as though it uses about 5 GB of storage for every hour recorded. I’m sure this will vary a little based on the type of content being watched, but it’s a good ballpark figure for the size SD card you may want to use.

The Fire TV Edition television does not have any kind of DVR functionality, so you can’t set it to record a channel at a particular time. It only records the channel that is currently being watched. Once you change to another channel, the recording is deleted and a new recording of the new channel is started automatically.

This means that, for example, if you watch a channel for 10 minutes and then channel surf during a commercial break, you will lose that 10 minute recording and not be able to rewind back to before you changed the channel. The TV does not just record everything you watch, from the moment you turn on the TV, in one massive recording, regardless of channel. It records one channel at a time from the moment you tune to a channel and discards that recording the moment you tune to a difference channel.

For this extended recording capability alone, I’d say an SD card is a must have item for any Fire TV Edition television, even if you don’t plan to use it to store additional apps, which is another use for the SD card slot.