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Blackboard File Sizes
A very important consideration when placing files in your Blackboard course is the size of the files. Remember that students must be able to access your files quickly and easily in order for your course to be successful.
Some of your students will be working from high speed internet connections. In this case,they will enjoy very rapid download speeds and will be able to access most files easily. Some of your students, however, will be working from a variety of connection types --dial up, DSL lines, cable -- that can greatly affect the speed with which your documents can be downloaded. Long download times lead to student and instructor frustration. The table below gives a quick summary of the speeds at which different file sizes download over a variety of connection types. You can use it to determine how best to deliver your files in
Blackboard.
|
Connection Type |
K/sec |
100K File |
1MB File |
5MB File |
10MB File |
|
14.4 Modem (older modem) |
1.5 |
66 sec |
11 min |
57 min |
114 min |
|
28.8 Modem |
3 |
33 sec |
6 min |
28 min |
57 min |
|
ISDN |
7 |
14 sec |
2 min |
12 min |
24 min |
|
T-1 |
150 |
1 sec |
7 sec |
34 sec |
68 sec |
File Size Comparison.
|
Original PowerPoint Presentation |
Original Presentation Converted to PDF |
Original Presentation with Compressed Images |
Presentation with Compressed Images Converted to PDF |
Text Outline in Word |
|
14,310,912 bytes 13.6 MB |
3,617,236 bytes 3.44 MB |
4,908,544 bytes 4.68 MB |
4,340,590 bytes 4.13 MB |
43,520 bytes .04 MB |
TWU does not have any official restrictions on file size. However, we do not recommend uploading files over 5MB.
A handy calculator for estimating the download time for different file sizes can be found at: http://billbrownmusic.com/calc.htm. Simply enter the size of your document and see how long it will take to download at various speeds.
Compress Your PDFs
Saving as PDF (portable document format) can save documents with more advanced formatting, like tables, and preserve the document exactly as you created it, but these documents can still be large.
PDF995 – This is a free download from http://www.pdf995.com and it can reduce PDF file size even more than Adobe Acrobat while retaining the same quality, but the free version requires you to view a sponsor page every time you use the application.
Zip Your Word or RTF Files
You can zip text files to reduce the file size. Remember that zipping PDF, JPG, and MP3 files does not reduce the file size, since these file formats are already compressed. However, text files (Word, RTF) can be reduced with the zip function. You can then upload them to Blackboard as a "packaged file."
Resources.
How to Reduce File Size in PowerPoint
http://office.microsoft.com/en-us/powerpoint/HA011168821033.aspx?pid=CH010036301033
Chart of equivalencies, e.g. how many kilobytes (KB) in a megabyte (MB) http://www.t1shopper.com/tools/calculate/
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