SL install slowed computer immediately

It depends on how many Dashboard Widgets you have open. Each client process can handle several (six, I believe) Widgets. They should only be taking up CPU resources when Dashboard is open.

When you're in Activity Monitor, make sure you are looking at "All Processes". Then try and find which process is taking up CPU time (if that's the reason for the slowdown).

Slowdowns can also be caused by being low on physical RAM. Check the number/size of your pageouts. It's an indication of how often the system has to swap a page to/from hard disk (a high percentage of pageouts vs. pageins).

Could SL be still indexing the drive for Spotlight? (Click on Spotlight and it'll show any drives that are being indexed.)

 

Personally I'm finding SL a pain in the butt, I never used to get Beachballs and little pauses when copying files, mouse click issues. I just can't face restoring to Leopard right now.

 

Lots of things can cause performance degradation, particularly after installing SL. For one, how long has it been since the installation? Some of the late night maintenance scripts your Mac runs might correct some of the problems. People have reported that performance improves a few days after the install.

You might try running "Disk Utility" in your Utilities folder and selecting the "Repair Permissions" command. It's an easy step and the beachballs that come from permission issues should disappear (or at least diminish). But to be honest, it could be a small percentage.

It also would be worth running the "Console" application in your Utilities folder. (Make sure "system.log" is selected in the lefthand pane.) You might not understand exactly what you're reading, but it might provide clues to underlying issues. For example, if you've got a specific problem, it's highly likely you'll see the same error message over and over. It might give you an idea of your next step, or post here and someone will have an idea.

mt

 

Right after you install SL, and reboot, spotlight will be indexing. Until that is finished your machine might be a little sluggish. I have SL installed on a new model 13" MBP and a 3 year old 15" MBP. Both run very well with no problems.

 

Please post with full information on the computer, amount of RAM, HD with open space available etc., then someone may be able to help. Without that info it will be basically general help or guesswork.
Also, download Onyx (freeware, available on macupdate.com) and run the maintenance scripts and at least the erase font caches option in the cleaning pull down (requires a reboot). The later is not really required but it can't hurt and I have found it helps sort things out.
I too suspect you are running low on RAM, take a look in the Activity Monitor.

 

I suggest you reboot your computer. After it restarts, trash that JPG image.

DMG files are disk image files. They are the most popular method of distributing OS X software. You double click on one and it mounts just like a drive in Finder.

I upgraded my wife's system on Sunday to SL. She runs FireFox v2 and has no issues with delay or lag. I upgraded to SL last week and run the latest FireFox, again with no issues. So I suspect that yes, the JPG maybe part of the issue and it is being used by FireFox. So let's start there and get rid of that offending file.

Take care,

 

Firefox is probably to slowest browser on Mac OS X. You can't do anything about that.