I am still on Lion as the list of apps that are not working with ML contains too many that I use.
Anyways, i've had this systemuiserver issue on and off since installing lion, but a search of the forums reveals many of thesame problem through from 10.4 to 10.8, ℹit looks as if every os x has had this issue and it varies from person to person.
I have not yet tried the playlist file option, but systematically turned off all things displayed in the right side of the menu bar.
Often this toggling of items would cause noticable changes in the cpu usage that systemuiserver was eating, particularly the clockâž–, which i was sure switching it off had solved the issue, but alas it just took longer to re-appear. however they were not sustained or consistent spikes in the activity of that actual SystemUI process.
tonight i tried toggling the wifiâž•. Switching it on the SysUIserver pops right up to danger levels of 80-90%, switching the wi-fi off does nothing initiallty, but after about 20-30 seconds the Sysui drops back to a moderate 0.5% - 2%.
This wi-fi toggle scenario has been repeated time and time again and is the only consistent cause of the change to the systemUIserver cpu usage problem in my situation.
I am now using the LAN cable in the ethernet port instead with no problems.
I have a 2010 Imac with 4gb of ram and all sorts of peripherals from lacie 2TB drives (x3) and a presonus 24 track digital desk, usb hubs coming from every port on the iMac and a second screen, along with 2 other heavily used sharing macs on the local network using airfoil and itunes home sharing, i also remotely control the mixdesk with the ipad and often use the local network for multiple apps running over each other.
I will continue to test this theory tonight by operating the antenna without being associated with a network and see if the problem still occurs.
Hope this will ease the frustration that at least some of you are having from the same problem, although it appears from the varied reports that it could be a general problem with any right side system menubar item, depending on the setup of your machine, but beyond my little fix the discovery of the root cause is for the coders who understand events behind a click or a keystroke.
good luck, and may the sauce be with you.👿
BTW i would apppreciate any solution that doesn't involve my machine having an un-usable wi-fi card.