Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I develop software on a Macbook Air 1.6 Ghz but find running Rails test suites and generators on this computer very slow. I'm thinking about buying a Linux tower to put on my local wireless network to do my Rails development on. I would want to use my Macbook Air and ssh into the Linux box and do my development with Gnu Screen, vim, etc.

Can I expect the keystroke and echo latency for a ssh session between two machines on a local wireless network to be negligible?

Does anyone develop using this kind of local setup? What CPU speed is your Linux box?

share|improve this question
up vote 1 down vote accepted

I am using a similar setup - Macbook Air, wireless to router, wired to Linux server; all on local network.

I don't have actual timings for keystroke and echo, but I can type just as fast in the ssh shell (using Emacs or nano) as I can on the Macbook. I doubt you will be able to tell the difference.

The only difference I notice is that the Linux box may have gone to sleep while I was reading mail or some such on the Mac; then it can be a few seconds delay to get a response when I start using Linux again. But this can obviously be tuned by setting a longer sleep timeout.

share|improve this answer
Thanks for the response. What CPU speed is your Linux box? – dan Dec 29 '10 at 2:37
Intel i7 920, 2.66 GHz. But CPU speed shouldn't matter for typing speed, if there are problems they will presumably be from network delays. – j-g-faustus Dec 29 '10 at 3:03
About how much faster is your Linux box than the Macbook Air for things like running unit tests? – dan Dec 29 '10 at 4:49
Don't have hard numbers, but subjectively "quite a lot faster". For single threaded, CPU bound stuff (Ruby, Rails, shell scripts etc.) the difference isn't as large as you'd think, but the Linux box stays responsive even when it's doing a lot of stuff simultaneously. IMHO the Air (early 2008 model, 1.8GHz CPU, 2GB RAM, SSD) is borderline weak for development, while my Macbook Pro (2.5GHz, 4GB, plain hard drive) isn't. – j-g-faustus Dec 29 '10 at 14:20
Thanks. I ordered a Dell XPS 7100 with ubuntu pre-installed. Not as fast as an i7 CPU but it should still be a lot faster than my Air. – dan Dec 29 '10 at 14:31

How fast can you type? ;-) You'll be fine. I use ssh extensively over wireless-g at home, typing about 70 wpm and using screen, vim, mutt in a 160x50 character terminal window and its fine. You're more likely to encounter latency if you were going out over the Internet or when dealing with a slow server. Unless you have a poor wireless signal, I don't think you would perceive the latency much more than that over a wire. A word of advice though, you might find it hard to find a good wireless card for Linux, so I'd recommend using ethernet directly hooked up to your router/switch.

If you want something more convincing. just try pinging your wireless router from your Mac. If you see response times of a few milliseconds, you should be fine. Anything more than 10 and you might see some noticeable lag, but it should stay pretty constant. You're most likely to see the latency when doing something that refreshes the whole screen, such as scrolling through a man page or a log in less.

share|improve this answer
Thanks for the response. What CPU speed is your Linux box? – dan Dec 29 '10 at 2:37
Well, its not just one. I connect to several, anywhere from a PIII 600MHz to 3 Ghz 8-core Xeon. Its not really the speed of the processor though so much as what the server is doing. Some of my fastest machines are doing a lot and might get loaded down with things to do and then the connection gets laggy sometimes. Other times, I'm connecting to hosts across the net and then depending on the remote network, it will be fast or slow. The point is, its usually not the medium over which you ssh that slows it down, its other factors that slow it down. – deltaray Dec 29 '10 at 3:11
Thanks for the feedback. – dan Dec 29 '10 at 15:08

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .