I put 12 gb of ram in my imac and it lags a lot

Question

i have a total of 12 gb of ram in my 2012 imac and it lags in many simple programs such as iPhoto, iTunes, ect. And in more complicated programs such as photoshop cs6 and other Adobe programs. I usually get bouncing icons for about a min before anything happens or spinning color wheel. Any idea as to y this is happening? I have taken the iMac to geek squad 4-5 times with the same issue every time. I put the ram in after the second time and no improvement. This last time they replaced my stand and didn't tell me Why!! I only have about 250 gb used out of the terabyte it can hold. I am just so frustrated. Any help would be appreciated. Also I am not that good with computer terms.:)

Answer 1

When you see a beachball cursor or the slowness is especially bad, note the exact time: hour, minute, second.  
These instructions must be carried out as an administrator. If you have only one user account, you are the administrator.
Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad and start typing the name.
The title of the Console window should be All Messages. If it isn't, select
          SYSTEM LOG QUERIES ▹ All Messages
from the log list on the left. If you don't see that list, select
          View ▹ Show Log List
from the menu bar at the top of the screen.
Each message in the log begins with the date and time when it was entered. Scroll back to the time you noted above.
Select the messages entered from then until the end of the episode, or until they start to repeat, whichever comes first.
Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.
The log contains a vast amount of information, almost all of it useless for solving any particular problem. When posting a log extract, be selective. A few dozen lines are almost always more than enough.
Please don't indiscriminately dump thousands of lines from the log into this discussion.
Please don't post screenshots of log messages—post the text.
Some private information, such as your name, may appear in the log. Anonymize before posting.