Test network speed without wasting disk

dd if=/dev/zero bs=4096 count=1048576 | ssh user@host.tld 'cat > /dev/null'

The above command will send 4GB of data from one host to the next over the network, without consuming any unnecessary disk on either the client nor the host. This is a quick and dirty way to benchmark network speed without wasting any time or disk space. Of course, change the byte size and count as necessary. This command also doesn't rely on any extra 3rd party utilities, as dd, ssh, cat, /dev/zero and /dev/null are installed on all major Unix-like operating systems.

Sample Output

user@host.tld's password:
1048576+0 records in
1048576+0 records out
4294967296 bytes (4.3 GB) copied, 171.841 seconds, 25.0 MB/s

By: atoponce

2010-06-08 18:49:51

dd ssh ssh dd

Submit An Alternative

What Others Think

This will compress really well with ssh (/dev/zero is the same byte over and over). For a better test replace /dev/zero with /dev/urandom,

sdadh01 · 677 weeks and 1 day ago

The SSH connection is adding overhead with encryption, thus the reason to use /dev/zero to level the playing field, otherwise, your bandwidth will be considerably less.

atoponce · 677 weeks and 1 day ago

Or you could use netcat and use /dev/urandom. This way you don't have the overhead of compression and use a more realistic approach to test your network. dd if=/dev/urandom bs=4096 count=1048576 | nc host.tld 1234 and on host.tld you should start netcat with the 'listen' parameter nc -l -p 1234 | dd of=/dev/null Actually, if you really wanna test your network you should go the iperf or netperf way (and use UDP or TCP, depending on how you wanna test it).

paragao · 677 weeks ago

Right. This isn't meant to be an accurate network bandwidth benchmarking tool. This is useful for nothing more than a rough estimate, and it doesn't rely on any external 3rd party tool, and it's cross platform, which was the goal.

atoponce · 677 weeks ago

this command is helpful for a 'rough estimation' but i would add the ssh '-c arcfour' option.

cp · 673 weeks and 4 days ago

Travis Scott Jordan 1 Air Jordans Jordan 11s Jordan 11 Jordans Shoes Retro Jordans Moncler Jackets Nike Air Jordan Moncler Outlet Off-White Off White Shoes NFL Jerseys Jordan Shoes Jordans Shoes Yeezy 350 V2 Adidas Yeezy Yeezy Yeezy 700 Yeezy Nike Outlet Yeezy Shoes UNC Jordan 1 Jordan 13 Jordan AJ 1 Yeezy Foam Runner Nike Outlet Nike Outlet AJ1 Yeezy Supply Yeezy Zebra Jordan 1 Low Air Jordans Pandora Charms Adidas UK Nike Store Adidas Yeezy Official Website Yeezy 350 Jordan 1 Nike Outlet YEEZY SUPPLY Pandora Charms Nike Shoes Nike Outlet Pandora Outlet Jordan Shoes Air Jordan 4 Pandora Jewelry Pandora Rings Pandora Bracelets Adidas Yeezy Yeezy Pandora Charms Nike Outlet Adidas Yeezy Air Max 720 Nike Air Max 270 Air Jordan 11 Air Force 1 Air Jordan 1 Nike Jordans Jordan 1s Pandora UK Nike Jordan 1 Jordan 1 Yeezy Slides Nike Air VaporMax Nike Vapormax Flyknit Air Jordan 1 Mid Adidas yeezy Yeezy Shoes Adidas Yeezy Yeezy 350 Nike Shoes Nike Outlet Yeezy NFL Shop Official Online Store Nike UK Yeezy Yeezy 350

jiuer7845 · 90 weeks and 3 days ago

rahimhh21 · 39 weeks and 2 days ago

Perfecthomepugs · 30 weeks and 3 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Similar Commands

Double your disk read performance in a single command

Test your total disk IO capacity, regardless of caching, to find out how fast the TRUE speed of your disks are

Testing hard disk writing speed

Test your total disk IO capacity, regardless of caching, to find out how fast the TRUE speed of your disks are

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)