As the length of the lectures vary, so do the files sizes. Individual lectures (usually 1 hour to 1 1/2 hours long) generally run between 10MB and 20MB in size. Complete series are divided up into parts that usually range from 15MB to 30MB in size.
While a number of factors—such as location, network traffic and the quality of the connection—can affect download times, in general the chart below gives a decent approximation of download times for a variety of connections.
Connection Type |
Download Speed
(kilobits per sec) |
Download Time for 10MB file |
Modems |
14.4 Kbps
28.8 Kbps
33.6 Kbps
56.0 Kbps |
97.1 min
48.6 min
42.5 min
25.0 min |
ISDN 1-channel*
ISDN 2-channel* |
64.0 Kbps
128.0 Kbps |
21.9 min
10.9 min |
T1 |
1,544.0 Kbps |
0.9 min |
HDSL |
768.0 Kbps |
1.8 min |
ADSL |
1,544.0 Kbps |
0.9 min |
Satellite |
128.0 Kbps |
10.9 min |
Cable |
4,000.0 Kbps |
0.4 min |
Please note that these times are approximations only.
