I think I need it mostly for the high resolution screen, which would make long readings on the internet much more easy on the eyes and enjoyable and less tiring for the eyes too.
Since the high pixel density is not available on external monitors, I am thinking of probably buying Mac retina or windows equivalent.
Budget, I guess $2000 or less is okay.
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By the way, I took out the 8gb ram in my 2009 MacBook Pro to return the RAM because since one slot is out I didn't think one stick was useful, so it would be better to return it and buy 4GB Ram.
To replace it, I put in the 4GB stick from HP laptop, but when I boot it, it started making beeping noise every 3 second and the screen won't turn on.
Is the RAM that came with the HP laptop incompatible with the 2009 Mac?