Mountain Lion - Screen share over WIFI

I've noticed this as well. At first I thought it was the Mac Mini running very slow but if I use the connected keyboard it responds normally. Using Share Screen over Wi-Fi is painfully slow and unresponsive - like 30 seconds for an action to be acknowledged. I have the newest Airport Extreme running my Wi-Fi.

Hopefully we'll see a fix in 10.8.1.

Edit: I should add that if I go back to Wi-Fi screen sharing after interacting with the Mac Mini directly with a keyboard, the screen sharing over Wi-Fi returns to normal.

Same issue here. Was using screen sharing from my 2008 iMac to my 2012 MacBook Air just fine. Upgraded to Moutain Lion and now it's so slow to be completely unsuable.

I hope this doesn't get missed in the next update.

I had to into my router's configuration and change it to WiFi "N" which is 5Ghz. After that it has worked fine. To see what your WiFi protocol is, hold down the option key while clicking the menubar WiFi icon. After "PHY mode: 802.11" you should see an "n". If it reads any other letter then you are using slow wireless.

@Gnarlodious - I don't think it's anything to do with G or N setting. I'm using the latest dual-band Airport Extreme and am having this problem. The issue did not occur under Lion so this appears to be a Mountain Lion issue. Sometimes it does work sometimes it's very VERY slow.

Gnarlodious wrote:

I had to into my router's configuration and change it to WiFi "N" which is 5Ghz. After that it has worked fine. To see what your WiFi protocol is, hold down the option key while clicking the menubar WiFi icon. After "PHY mode: 802.11" you should see an "n". If it reads any other letter then you are using slow wireless.

All wireless is slow, not just A/B/G

Same problem here. One machine on Lion and one on ML.

Screen sharing runs in spurts and is has become horribly bad.

Tried reboot of routers, machines, modems

nothing

sweet set is now...NOT SO SWEET.

I'm also experiencing slow screenshare issues when trying to control my MacBook from my MacPro. I have a wireless N network setup on a Linksys E2000. The MacBook is connected to the router via ethernent and the MacPro is on wifi. I had no problems with this setup before Mountain Lion and it appears to be gradually getting worse for some reason. Any ideas?

I've experienced the same slow screen sharing issue. I'm using a 10.8 screen sharing client connecting to a 10.7.4 host over the Internet (WAN). I found that if I use the iCloud "Back To My Mac" screen sharing connection, it's super slow and completely unusable. If, however, I connect directly to the host via IPv4 address or host name (Connection menu -> New... while in Screen Sharing application), the connection is speedy like it was with the 10.7.4 as the client. This is reproducible. It seems apparent that it's a problem with either the use of the IPv6-to-IPv4 tunnel, iClound's Back To My Mac service, or the 10.8 Screen Sharing client's use of these.

I glad it's not just me - I use screen sharing at home all the time. I had a screenless Macmini that looks after iTunes amoungst other things. I manage it from My Macbook pro. My Mac Mini is connected direct to the router and my MBP is connected wirelessly. I never had any problems prior to upgrading both from Lion to Mountain Lion.

The screen does not refresh unless I click in the windows andit often breaks down into large pixels. It is totally unusable.

I have no faith in Apple to fix this. They dont participate in the these forums and they never respond to feedback.

Lion broke iMovie on some Mac models - I had to wait for Mountain Lion to see that fixed.

I'm having the same problem. So far, the only solution that has worked is restart screensharingd on the machine that I'm connecting to:

sudo killall screensharingd

That causes the server to restart. The client seems to auto-reconnect pretty quickly.

It'll start slowing down again, so I just setup a crontab to restart it every 10 minutes.

sudo crontab -e ...

*/10 * * * * killall screensharingd

Hacky solution, but it works.

This isn't fixed in 10.8.1

I'm having the same issue as well. I have a new macbook pro that I use to connect to another mac running Lion. I recently upgraded the macbook pro to Mountain Lion and ever since, my screen sharing connection has been extremely slow. The only useable workaround I have found so far is to connect to the lion box using a vnc client. I have searched quite a few message boards and none of them have had a fix that works for me.

Hopefully Apple will fix this sometime soon.

I used to use screen sharing to connect to my headless (no monitor) mac pro early 2008 running Lion from my early 2009 Mac Book Pro 17" also running Lion. I had them connection view internet sharing over an ethernet cable. There was no lag, I could eaisly use program and even watch video.

After upgrading both to Mountain Lion now screen sharing is usless. Apps are slow, mouse movements do not track well and forget about video, it doesn't even render.

I did notice something interesting, if i do connect a monitor to the headless mac pro the issues go away. Everything runs smooth like it used to headless on 10.7 until i disconnect the monitor, then back to slow town.

Just installed 10.7 on another HD so I continue to use the computer, worthless with 10.8.

cured! latest update seems to have restored.

hoorah

Which update? 10.8.1? Both machines are running 10.8.1 and both still have the problem. It's definitely a "headless machine" issue for me i.e. if I start my Mac Mini with the TV on a different HDMI channel then it has the issue. As soon as I switch to the right HDMI channel it come right and speed returns to normal. It looks like Mountian Lion doesn't like running headless while screen sharing.

the Lion machine is running 10.7.4, the ML machine is running 10.8.1.....

perhaps i overstated things...intitiaiting sharing from the 10.7.4 machine to the 10.8.1 machine is working flawlessly - maybe even with less lag then before these problems. I have no need for the reverse so I have not tried it...but I will when I can and i'll report back.

Not sure how you are defining "headless" Both of my machines are minis. I run the 10.8.1 machine (2012 mac mini) through an HDMI cable to a TV but when screen sharing, that TV is always off. The 10.7.4 (2009 mini) machine uses a regular monitor interface and some crappy montior that has so many stickers on it i don't even know what it is anymore.