Is it more useful to display the current speed or average speed for a download/upload?

Question

I'm working on an interface for uploading videos to a website and currently we display the average speed for the upload to the user, as well an ETA derived from this average rate.

I was wondering if it is perhaps more useful to display the current speed of the upload instead of the average speed.

1) I think given we already display the ETA to the user, the average speed is redundant information. Same information, just a different metric.

2) One specific instance where I believe this would be more useful information is in the case that the user has a high initial upload speed, say 4mbps, for several minutes that then drops down to dialup speeds, 56kbps. The average speed displayed would slowly start to go down (given the weight of 4 minutes at a higher speed), giving no indication that the user's upload rate had dropped greatly.

Worth mentioning, the original argument for using the average speed over the current speed is that the current speed can be too "jumpy". I see this as both a blessing, in the case of the 4mbps drops to 56kbps and the user being aware of the change, as well as a curse, the "jumpiness" of a normal connection.

I'm interested to hear others thoughts on this. Thanks!

Answer 1

The best option may be to do something in between. If you are showing the average rate for the last 5 seconds (or whatever amount of time works best for you), then you should minimize the jumpiness, while still reacting in a timely manner to large changes in speed. In your example, this method would show 4 MBps for the first few minutes, and would go down to 56 KBps 5 seconds after the drop. However, if the connection jumps up to 6 MBps for a fraction of a second, the average should help prevent the displayed number from greatly increasing (which can confuse users.)

You didn't ask about it, but this may be a better way to calculate your ETA. I would recommend using a longer average than 5 seconds, but this would better account for a large and permanent jump. This would have your ETA timer become more jumpy, but it may also be more accurate. Something to consider.