To replace my mid-2011 iMac (12 GB RAM, 2.7 GHz i5, Radeon 512 MB), whose Radeon Graphics card is slowly passing away, I purchased a mid-2011 Mac mini (10 GB RAM, 2.5 i5, Radeon 256 MB) with same HD capacity, and carried over my data with Time Machine.
After successfully repairing an issue with the Startup Volume in Recovery mode, I am finding the mini to be incredibly slow to do anything. For example, opening a Finder window takes a good 2 minutes. Even my mom's never-upgraded 2009 iMac is much, much faster with lesser specs.
Since I migrated the data from a (rather fast) iMac, I am ruling out malware or system cache issues. I didn't see anything peculiar in Activity Monitor and Disk Utility says all is okay.
My first suggestion would be that the culprit is the Ram that is installed being from different vendors and capacity, but I am baffled to find out how I could be sure that this is the problem before I open it up in case I have to return it.
What is possibly making this Mac mini so slow and how can I know for sure?