Table of Contents
Speed meets -v
…or: Why I will not copy files using a GUI
This document was inspired by a thread on a mailing-list I have subscribed. The thread was about the speed of different file-systems (ext2, ext3, reiser, xft, …) One of the folks timed the speed using the KDE-Drag'n'Drop function.
So I took the time to time different methods of copying files. I also tried different 'locations' like a regular TTY or an xterm at different window-sizes.
I did not take different file-systems into account, since I do not think that speed is an important issue when choosing the FS. If I want a logging-FS for security reasons, I don't care for the speed-penalty I get for writing that log.
The box and its contents
I used an old P3-600 for this test. Debian Woody is installed pretty much out-of-the-box. That means that there were not much optimizations like DMA for the disks or the like.
For the tests, I copied the contents of /dev/hda1 (my root-partition) to /dev/hdb1 I used the 'time'-command for timing. Read its manual-page for details
Here are some numbers for those interested
woody:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/hda1 3.9G 1.1G 2.6G 29% / /dev/hdb1 19G 1.1G 16G 7% /mnt/hdb1 woody:~# uname -a Linux woody 2.2.20-idepci #1 Sat Apr 20 12:45:19 EST 2002 i686 unknown woody:~# find / | wc -l ; # Number of files 144281
Ready, set, go!
| Command |
Environment |
real |
user |
sys |
| cp -ax / /mnt/hdb1/ |
tty, 80x30 (should not matter) |
15m21.664s |
0m15.380s |
5m6.830s |
| cp -axv / /mnt/hdb1/
|
tty, 80x30 | 22m8.563s |
0m18.730s |
4m3.590s |
| xterm, 142x53 | 18m32.750s |
0m30.840s |
5m2.450s |
|
| xterm, 80x30 | 17m27.710s |
0m30.790s |
5m5.190s |
|
| Drag'n'Drop |
KDE |
23m28s (Hand-timed, +- 5 seconds) |
not available | |
| rm -rf /dev/hdb2/* |
tty, 80x30 (should not matter) |
2m11.933s |
0m0.400s |
0m3.210s |
| rm -rfv /dev/hdb2/* |
tty, 80x30 | 3m55.950s |
0m3.420s | 0m4.850s |
| xterm, 142x53 | 2m20.204s |
0m3.040s |
0m4.720s |
|
| xterm, 80x30 | 2m20.208s |
0m3.220s |
0m4.940s |
|
| Drag'n'Drop | gmc (konqueror did play tricks on me :-) |
3m40s (Hand-timed, +- 5 seconds) |
||
And what does this tell us?
- File operations on commandline without the -v swich are fastest (by far!)
- When being verbose, an xterm can be faster that a TTY (I did not expect that. Probably depends on your graphic-adaptor)
- GUI is slowest. Not only by time.
But why is GUI so bad?
It took me several attempts to hand-time the Drag'n'Drop.
- The system crashed when accessing /dev/mem (This was never a problem on the commandline!)
- When I came back from my coffee, I noticed that a dialogbox was waiting for my answer. This box appeared quite a while after starting the operation.
- When I came back from my second coffee, I had missed the end of operation. While this is not really important in real life, it shows how inaccurate the 'remaining-time' display is.
So judge yourself...
I am not against GUIs. But if you need to copy a lot of files, take the keyboard. I usually try out the command with -v and when I see it works like I want it to, I hit <ctrl>+C and restart without -v. That way I can also spot error-messages, which is hard or impossible with verbose on.
