More SSD and HDD Comparisons and Testing Methodology [Update]
Walt Mossberg weighs in on the Solid State Drive (SSD) vs Hard Disk Drive (HDD) debate. The issue has become relevant now that Apple offers a SSD option on the MacBook Air, and this feature will certainly trickle down to future Apple laptops.
An earlier comparison from Arstechnica was difficult to interpret due to differences in machines (1.6GHz vs 1.8GHz) and non-standardized testing.
Mossberg offers at least one piece of standardized data on the SSD vs HDD comparison in the MacBook Air. He compared two 1.6GHz processor MacBook Airs which only differed in the type of hard drive (SSD vs HDD) and ran a standardized test case: "turn off all power-saving software, set screen brightness to maximum, turn on the Wi-Fi and play an endless loop of music."
As always these tests come with some considerations. After some investigation, it appears that iTunes explicitly turns off Mac OS X's file caching, so the drives are being accessed with regularity in this test. This drive access, however, is small and sequential which does not take advantage of SSD's strengths (random non-sequential). With these notes in mind, the results of the test revealed almost no difference (5 minutes in favor of SSD).
Not all SSDs, HDDs and laptops are made equally, however. Mossberg also compared a Toshiba Portege R500 with a 1.8" HDD and a 1.8" SSD drive. In the same test, Mossberg found the Portege R500 ran 1 hour and 21 minutes (36%) longer with the SSD. Now, the reason for this large difference is unclear. Update/Correction: the Toshiba also uses the 1.8" drive, not the 2.5" drive previously reported here.
Similarly, MacLife found that the 32GB DVNation SSD drive installed in a MacBook Pro saw 55% increased write speeds and 88% increased read speeds compared to the stock HDD. They also saw similarly dramatic speed increases in "real world" tasks as well as a 14% battery life gain with the SSD drive.
As a result of these discrepant findings, the SSD vs HDD debate will likely be reintroduced with every new laptop introduced, as findings seem to vary by individual model and task. At this point, however, it seems the accepted advantages for the SSD drive in the MacBook Air is a more responsive user experience, and less vulnerability to data loss.