I have just upgraded from MBP 2008 Unibody running 10.6.7 to MBP 2011 running the exact 10.6.7. The issue that I had is that upon a fresh restart, I see significant increase of RAM usage between the two. iStat is installed in both laptops and upon fresh restart MBP 2008 has about 930 MB on some boot-ups and 1.05 GB RAM on others. For MBP 2011, the RAM usage is between 1.3 GB to 1.4 GB RAM. Both has similar start-up application e.g. dropbox, istat, growl and standard apps. All I can identify is that the built-in graphics shared memory between 2008 and 2011 is different by 128 MB (256 vs 384 MB), however, the RAm differences between the two after boo is about 400-500 MBs. Is there a good explanation for this? I mean the OS is the same, the hardware shouldn't impact the RAM usage that much, should it?