Chromebooks and the Mighty USB Port – Useful even in the Age of the Cloud

3/21/2014

Another benefit of Chromebooks for use in an educational setting is the practicality of the mighty USB port. Those that follow me know I am a huge fan of having options for transferring content on and off devices. This is something I insist on having with the Windows 8 tablets I routinely use. After all, I should be able to easily transfer my content that I create without having to go through an obstacle course of inconvenience.

For Chromebooks that have the reputation of being useless without a WiFi connection a USB port suddenly opens new doors of access to all types of media offline. Of course there are workarounds for using Google Apps offline, but these do need setup ahead of time. The USB port makes it extremely convenient to transfer files on and off the Chromebook.

One of the glaring weaknesses of the iPad is that it is not that easy to get content on and off the device for shared users. Sure you can upload content to iCloud, Google Drive, or OneDrive but that requires a strong wireless connection and a separate userid and password for the other services for each individual iPad account. You could also connect the iPad to another Mac or PC via a USB adapter and copy the files, or email the content to yourself as an attachment. All of these methods will work but this workflow falls apart in the classroom where devices are often shared among different students. The iPad does not support multi-user accounts, the Chromebook does.

One of the biggest deterrents for sharing digital projects is the large file sizes that take time to upload and download during class time. It is difficult enough to do this by yourself but when you have 10, 20, or 30+ students all trying to upload their finished video project to the Cloud at the same time it only exacerbates the problem. Any teacher that has tried class projects knows that the more users there are sharing a wireless connection the slower it will get…. until it is unbearable to even use.

In times like these a simple USB port is worth its weight in gold.

I did a little experiment the other day and thought I would share the results. These are practical real-life examples to give you an idea of the time commitment of uploading/downloading large files to the cloud.

Here is a common scenario, a teacher wants to load a video on a classroom set of 30 Chromebooks so students can have access to a flipped classroom video lesson after school. To explore this scenario I chose a typical 10 to 15 minute video project in the MP4 format that I regularly post up to the ITC YouTube Channel. I chose Episode 33 of ITC Techshare that was 13 minutes and 45 seconds long with a file size of 330 MB.

First, I needed to get the video from my Windows 8.1 Desktop PC to a USB drive. No problem, I connected an 8GB USB flash drive to the USB port of my Desktop and copied the file from the Desktop to the USB drive. This completed in about 65 seconds with an average copy speed of 5.54MBps.

USB Flash Drive (copying from PC hard Drive to USB flash drive)

330MB – 65 seconds

If all students had reliable broadband Internet connections at home teachers could just let students stream directly from YouTube, unfortunately many do not.

I next inserted the USB drive with the video file I just copied using my PC into the Chromebooks USB port. Here you have a choice of ports, the Acer C720P has two USB ports. The one on the left-side is USB 3.0.

I copied the 330MB file from the Chromebook USB port to the “Download” area of the Chromebook using the File Manager. 

The total time it took to copy this one file from the USB drive to the Chromebook hard drive was approximately 25 seconds using the USB 3.0 port of the Chromebook. Reading files from a USB flash drive is usually faster than the write speeds to a USB Flash drive thus the reason for the faster copy times to the Chromebook hard drive.

USB Flash Drive (copying from flash drive to Chromebook hard drive)

330MB – 25 seconds

Note: Chromebooks are basic devices and only let you save files to the “Download” folder of the hard drive. 

The Acer C720P Chromebook model that I have has both USB Version 2.0 and Version 3.0 – Version 3.0 is about 10 times faster than 2.0 so I always use it, especially for large file transfers. You do need a Version 3.0 compatible USB Flash drive to take advantage of these higher speeds. 

Performance details really matter and can add up to a lot instructional time wasted waiting for things to copy so I always choose the fastest and most efficient possible.

One Chromebook done, 29 more to go…

Of course, I would have multiple USB drives and setup a workflow for my students to help with this task in this scenario but this direct method of copying from a USB drive is the most efficient I have found.

In scenario 2 I would like to have my students upload the 330MB instructional video to their Google Drive. Since Chromebooks require a Google account Google Drive is included as part of the account and this makes for a nice workflow as students do not have to login to another cloud service like Dropbox or OneDrive. Other services require yet another userid and password and it is something to consider when weighing the hassle factor of multiple userids. 

Since I already had the video file copied to the Download folder of my Chromebook I selected Google Drive from the Apps Launcher on the Chromebook and then selected Upload. 

I navigated to the Download folder and selected the 330MB video file and pressed Enter. Below is a table of the Upload timed results.

Google Drive

Upload Times from Chromebook hard drive to Google Drive

0MB

82.5MB – 1 minute 35 seconds

165MB – 3 minutes 20 seconds

248MB – 4 minutes 49 seconds

330MB – 6 minutes 24 seconds

I also wanted to see what the Download time would be.

Download Times from Google Drive to Chromebook hard drive

0MB

50MB – 25 seconds

100MB – 53 seconds

150MB – 1 minute 25 seconds

200MB – 2 minutes

250MB – 2 minutes 30 seconds

300MB – 3 minutes

330MB – 3 minutes 25 seconds

Downloads are typically faster than uploads on most wireless networks. Below is a screenshot of our on campus wireless network speeds.

17.84 Mpbs Down and 11.68 Mbps up are pretty impressive speeds. At home I am lucky to get 2 Mpbs download speeds. 

The time it takes to upload/download large files is directly related to the speed of your network. The faster wireless you have the less time it will take. The other factor is capacity of the wireless connection so the more users you have utilizing wireless the slower the network will become for all users.

OneDrive

I was also curious about the OneDrive Cloud storage option so I also did some time tests for OneDrive. The results are below.

Upload Times from Chromebook hard drive to OneDrive

0MB

82.5MB – 3 minutes

165MB – 6 minutes 20 seconds

248MB – 9 minutes 33 seconds

330MB – 12 minutes 38 seconds

Here is what the OneDrive upload looks like:

Download Times from OneDrive to Chromebook hard drive

0MB

50MB – 1 minute 35 seconds

100MB – 2 minutes 47 seconds

150MB – 4 minutes 04 seconds

200MB – 5 minutes 16 seconds

250MB – 6 minutes 30 seconds

300MB – 7 minutes 47 seconds

330MB – 8 minutes 37 seconds

Overall OneDrive upload/download speeds took about twice as long as Google Drive. Google Drive did give me a status message saying it would not scan the files or check for viruses so that may be the reason it went faster.

So let’s take the best case of uploading the 330MB video file to Google Drive, it took 6 minutes and 24 seconds for me to upload one file from the Chromebook hard drive to Google Drive on a high-speed wireless Internet connection by myself. 

If I added ten or twenty plus students to this equation it would bring those upload speeds to a crawl. Thus the problem with Cloud computing at the scale needed for schools. Most classroom teachers want to do uploads/downloads in mass at the same time and the technology is often not fast enough to keep up.

The numbers I have shared are real-world numbers. This is typically what happens with a classroom Cloud project in real life so I always take it with a grain of salt when I hear “sales people” talk about how grand the Cloud is. It is important to know the limitations of the technologies so you can avoid frustration. 

It takes experience to determine workflows that will work at the scale needed in the classroom. One-to-one learning environments are wonderful but the entire system must scale in order to be successful enough for all teachers and students to use in a practical manner.

Thank goodness for the USB port on Chromebooks.

Keep on Learning,

Tom Grissom, Ph.D.

@tomgrissom

http://eiu.edu/itc

http://techtalk4teachers.blogspot.com