hi- i recently purchased a june '09 13" mbp (2.53/4GB) as an "upgrade" from my oct '08 15" (yes 15") mbp (2.4/4gb). (i say upgrade because although it's a got a smaller screen, every component known to me is the same or better in the 13" mbp. i had to get a 15" at the time because i needed firewire; i sold & re-bought when the new 13" with firewire was announced.) i transferred the hard drive (which was an aftermarket hitachi 320gb 7200 rpm drive) from the old machine to the new, so the OS was the same (10.5.7 (9j61) for both; *not* the upgraded build of 10.5.7 for the june '09 releases). both machines had 4gb ram, although the oct '08 model had memory supplied by OWC and the june '09 model's memory was chips installed by apple. for both machines, i only used the integrated nvidia 9400m chip. (the 13" mbp doesn't have the 9600m discrete chip, and i disabled it on my 15".) i know benchmarks are not everything, but i noticed something a little peculiar -- particularly with respect to the disk test. any ideas? xbench reports the following: 1) "old" 15" mbp: overall: 132.93 cpu: 160.12 thread: 265.54 memory: 181.74 quartz graphics: 191.71 opengl: 143.63 UI: 296.70 disk: 46.33 2&3) new 13" mbp: (number before slash= before firmware upgrade / number after slash = after SATAII firmware upgrade) overall: 138.27 / 133.97 (green = better than oct '08 mbp) cpu: 168.61 / 170.29 thread: 302.24 / 315.71 memory: 182.53 / 188.56 quartz graphics: 202.24 / 178.20 opengl: 157.04 / 138.31 UI: 329.67 / 330.52 disk: 46.10 / 45.37 (red = worse) 4) "old" mbp with a 250gb 5400rpm apple-supplied hitachi drive swapped from the brand new 13" mbp -- running 10.5.7 build 9j3050 overall: 137.10 cpu: 159.62 thread: 268.92 memory: 184.08 quartz graphics: 190.15 opengl: 150.10 UI: 301.33 disk: 49.02 (=best of the bunch) the machines all rate fairly close in the "overall" category. what surprised me was that the supposedly "better" 7200rpm drive that i swapped over to the new mbp (a) immediately dropped down a bit in performance when i popped it in the new mbp and then (b) performed a little worse after doing the firmware update (SATA II). also, (c) the 7200rpm drive rated worse than the apple-supplied hitachi @ 5400rpm. i'm scratching my head on this one. could it be.... i) the 250gb 5400 rpm drive was absolutely clean and would likely decrease in performance over time? the old drive is 33% full. ii) that since i swapped hard drives, something in the earlier build of 10.5.7 is not optimized for the new mbps? iii) something else altogether? if (ii) is a possibility, is there any way for me to install that build as an upgrade to the earlier version of 10.5.7 without wiping the drive? (i'm sure 10.5.8 isn't that far away...and also 10.6 is coming, so that will make this question irrelevant in a few months.) thanks in advance for your thoughts.