Mountain Lion - Screen share over WIFI

Interesting that it's working with the remote running 10.8.1 - I had assumed the issue was with the remote machine. I'm running 10.8.1 on both.

By "headless" I simply mean screen sharing with a remote machine that may not have an active monitor - in my case it's attached to a 50" screen which isn't always on or might not be set to the HDMI channel that the Mac Mini is attached to.

ok - this works for me in BOTH directions - the only thing different since it wasn't workng working is the 10.8.1 update - not sure if the update iteslf fixed a bug or if it flushed a problem but I'm gopod to go.

As for your headless theory: there was no active monitor on the remote machine in both directions I tested this - so i'm guessing thatis a red herring.

Good luck!

Hmm, I still maintain it's somehow related to being headless. That is how I'm resolving the issue currently - e.g. typical scenario

1) Screen share from MBP to Mac Mini

2) Discover interaction to be painfully slow

3) Turn on "monitor" (TV) and/or switch to HDMI channel of the port the Mac Mini is connected to

4) Speed comes right

5) Switch off monitor, continue to screen share and speed remains fine until next time

I might try deleting some pref files and running permission repairs and see if that makes a difference.

@piksel I am having the same issue. I just setup an older mac pro last night and with the monitor connected screen sharing is working very well. I took the monitor off today to make sure it was going to still work, the machine in general, and I noticed the slowdown. I also noticed the resolution adjusted itself down, not sure what it was and what it went to haven't had time to look into that. But i concur it has something to do with the connected monitor. I also have apple remote desktop which I'm going to try. I don't know how well that works though firewalls though only ever used it locally. On that not remote desktop is pretty nice in that it lets you run remote commands copy direct from desktop to desktop and so on. Anyway, fun times.

Apple Remote Desktop is doing the same thing. I am also using remote desktop on an 06 macbook pro running 10.6 which works fine. There is no back to my mac function in 10.6 remote desktop is the only option. 10.8 headless remote desktop or back to my mac are slow to respond.

I'm running 10.8.1 on my new macbook pro and 10.7.4 on my older imac. Screensharing from 10.8.1 to 10.7.4 works extremely well but the other direction, 10.7.4 to 10.8.1 is extremely laggy. Obviously neither one of these systems is headless.

I am running 10.8.1 on my 2011 MBA and 10.8.1 on a 2010 mini server. The screen sharing has been so slow as to be non functional since upgrading to mountain lion on the mini server for me as well. It takes several minutes for a screen share window to appear, if it ever does, and once it is up it runs at an unusable slow speed. This occurs for me whether I have a display plugged into the mini or not and whether it is plugged in upon booting up or not. I will also note that I have a belkin router, not an airport.

Also I just checked my wife's MBA which is running 10.7.4, and it doesn't screen share the mini server any faster than my MBA running 10.8.1.

I'm running 10.8.2 on both machines now and haven't had the issue yet. It ~may~ be fixed...

I just updated both machines to 10.8.2 and the issue is persisting.

I personally gave up for now as Mountain Lion was causing me other issues. I reverted back to 10.7 and all is well but they should fix this.

There are two preferences in the Screen Sharing app that solved a painfully slow screen sharing experience for me after I upgraded one of my machines.

Access them by going to ScreenSharing-->Preferences. Click the preferences to "Encrypt passwords and keystrokes only (faster)" and "Adapt quality to network conditions (faster)." Especially the latter preference made a big difference for my situation.

These settings are on by default. I don't think they are the culprit for most of us who are having issues. I know my preferences are already setup for the fastest possible display, but screen sharing still shows issues.

Interesting. I had never visited them before and they were assuredly not set optimally for me. So maybe YMMV?It may be worth a look just in case. Just a thought. And they were the culprit for my situation--easily solved, so I guess I am lucky on this one.

The settings are not the problem for me either. I've tried other VNC clients and nothing can consistantly connect to the mountain lion imac. I've also disabled the firewalls on both systems with no change. The problem persists even when I have both systems on a switch by themselves. It's definately a mountain lion problem.