ScreenRecycler: Use your old Mac as a second monitor

ScreenRecycler use VNC and IS FAST. Just take a look at that video on the help page on screenrecycler.com. That is 100MBit Ethernet and playing full screen video on the second screen.

#5 - synergy is great, but 2 computers + synergy doesn't achieve the same result that ScreenRecycler is aiming for (i.e. ONE workspace spread across two screens).

I tried this application today, and while the idea is a good one it's not technically feasible at the moment. Setup was quick, but real-world application performance under ScreenRecycler was a different story entirely. VNC is a neat technology for accessing static (still) screens for small system administration tasks, but it is excrutiatingly slow at drawing all of the animations and window movements in a modern UI like the one in Mac OS X, even over a fast LAN connection. Every time I accidentally moused into an exposé corner the secondary display would be unusable for at least five seconds at a time. Even though the secondary display was somewhat usable for word processing, the sheer slowness of it negated any productivity increase I would gain by using multiple monitors. Put simply, ScreenRecycler is far too slow for real-world use in its current state. Unfortunately, it’s also not likely to get much better because VNC technology is simply not well suited to the task. One other problem I noticed was that whenever the ScreenRecycler application was active, Quartz operations on my PowerBook’s main display (such as Exposé) seemed choppier and seemed to use far more system resources. Let’s hope this is only a bug in the pre-release version.

When I was a child, my father would frequently remind me to "use the right tool for the right job." That’s exactly the problem here. There’s nothing inherently wrong with ScreenRecycler as an application; it's performance was not significantly worse than any other VNC server application I've tested. It’s just that ethernet, the technology that allows our computers to exchange files over networks, is not well-suited to transporting extremely high resolution uncompressed video in real-time.

My advice to anyone who thinks they need this is that they don't. If you have a computer lying around that you only want to use as a secondary desktop monitor, sell it and buy a real secondary desktop monitor instead. You will have a nicer and less cluttered workspace, and you will be able to use your applications and OS in the way they were meant to be used: quickly and efficiently.

Wow- I just installed this and am using my old compaq laptop as a display. Video doesn't seem to work that great, but for things like Activity Monitor or Terminal, it works fine.

Check out my additions to the group Flickr pool (abadcaffeinetrip/) to see it in action.

Couldn't you just use a direct firewire connection between the 2 macs? Just setup your own little dedicated firewire network, then there is no competition for ethernet/wireless network resources.

Correction: that link was wrong, this is the correct link for synergy:
http://synergy2.sourceforge.net/

Some of you might also like to check out Synergy. It's a nice cross-platform, open source package that does something similar to vnc. It's actually a lot more efficient and most people find it really amazing: http://sourceforge.net/synergy2/

And here is a picture of my setup:
http://www.flickr.com/photos/20after4/255359173
(Dual screen, Dual Processor G4 + AMD Athlon - all seamlessly connected)

I don't think it's very economic to let your whole old pc run only for using it's monitor via VNC. If you use it as a server or load off any other load then it makes sense. But if you only need the monitor, you're better of making a direct connection to the monitor with some soldering...

stu -

vnc works well over a network. you just need the ip and the port set up.

but in regards to this post/program - this would be GREAT for sys admins who want to have server stats up on a screen that doesnt need to be refreshed often (at least not quickly). a good way for a mac lab person to take advantage of older macs instead of throwing them out

Great idea. I just bought a new mac so this will be perfect.