When i have my macbook pro 17" Core 2 Duo 3.06Ghz, 8GB Ram plugged in at the wall, it is the greatest machine i have ever had. Really fast, perfect, however, when i unplug it from the wall, its like it becomes something else.
It is very laggy switching between windows, at launchpad and at the widgets page, and switching between them in full screen.
WHat shall i do? I travel around and it is really hacking me off
For performance issues, there are a few things you can check before resorting to hardware upgrades:
Check the following locations for apps that automatically launch on startup and delete any you don't need/want:
System Preferences > Users & Groups > yourusername > Login Items (SL and older: System Preferences > Accounts > yourusername > Login Items)
In Finder, click Go > Go to Folder > /Library/LaunchAgents
In Finder, click Go > Go to Folder > ~/Library/LaunchAgents
In Finder, click Go > Go to Folder > /Library/StartupItems
Remove any non-essential widgets you may have running, and uninstall any you don't need anymore.
Launch Activity Monitor and make sure at the top it shows "All Processes", then click on the CPU column heading once or twice, so the arrow points downward (highest values on top). Then look to see what may be consuming system resources.
Launch Activity Monitor and click the Memory tab at the top and sort the Memory column to see which apps are consuming memory. Look at the Memory Pressure graph at the bottom. If it shows green, you have plenty of RAM available for apps that need it. If it shows Red, you're maxing out your RAM.
Make sure you're not running any 3rd party antivirus app, as many of those will drain resources, reducing performance. They're not needed to protect your Mac. For more information, read the Mac Virus/Malware FAQ.
Use the YouTube HTML5 Video Player for watching YouTube videos, when available. (May impact fullscreen viewing. See link for details.) Not all YouTube videos are available in HTML5, but when they are, it will reduce demand on system resources.
Ad-blockers such as GlimmerBlocker will reduce the resource demands of loading webpages.
Maintain sufficient free space on your hard drive. 10% free space is good. More is better.
Disable or remove unnecessary or corrupt fonts using Font Book, which is in your Applications folder.
Turn off resources like Bluetooth or WiFi, when you're not using them.
Go to System Preferences > Dock and select Minimize using: Scale Effect. Uncheck "Animate opening applications".
Make sure your built-in Mac firewall is enabled in System Preferences > Security > Firewall
Uncheck "Open "safe" files after downloading" in Safari > Preferences > General
Uncheck "Enable Java" in Safari > Preferences > Security (applies to many older versions of OS X). Leave this unchecked until you visit a trusted site that requires Java, then re-enable only for your visit to that site. (This is not to be confused with JavaScript, which you should leave enabled.)
Be careful to only install software from trusted, reputable sites. Never install pirated software. If you're not sure about an app, ask in this forum before installing.
Never let someone else have physical access to install anything on your Mac.
Always keep your Mac and application software updated. Use Software Update for your Mac software. For other software, it's safer to get updates from the developer's site or from the menu item "Check for updates", rather than installing from any notification window that pops up while you're surfing the web.
Check the above for all user accounts that may be logged in. Log out any user accounts that aren't being currently used.
For faster startup times, make sure you've selected your startup disk in System Preferences > Startup Disk
If Parallels is consuming a high percentage of CPU resources, this may help.
