I have installed Snow Leopard today and did some testing with regards to its performance in booting, shutting down and launch times of applications. At the same time I check the RAM usage soon after the booting process is completed.
I have first done an upgrade of 10.6 upon my existing 10.5.8 installation and then (like it is always better to do in a complete new OS version) I did a clean install. The results are interesting.
I compared these numbers, with the timings I have recorded in the past with a 10.4.9 installation and a 10.5 clean install to see how Snow Leopard stacks up.
All tests are made in the same way on the same hardware (2GHz Core 2 Duo MacBook with 2GB RAM), averaging 3 consecutive measurements after each booting/shutdown cycle.
Though the absolute numbers are obviously not important, their relative value between different OS versions is what counts the most.
RAM usage (in brackets the differences wrt 10.6 clean install):
10.6 (clean install) --> 470MB
10.6 (upgrade from 10.5.8) --> 554MB (+15%)
10.5.8 --> 474MB (0%)
10.5 (clean install) --> 349MB (-35%)
10.4.9 --> 405MB (-16%)
10.4.7 on Power PC (Mac Mini) 206MB (-128%)
For the following measurements no reference to the Mac Mini with PPC processor are made, since the hardware changes are too radical (especially processor absolute speed, e.g. MHz, and 2 cores, rather than 1).
Booting:
10.6 (clean install) --> 27"
10.6 (upgrade from 10.5.8) --> 38" (+29%)
10.5.8 --> 41" (+34%)
10.5 (clean install) --> 44" (+39%)
10.4.9 --> 26" (0%)
Mail:
10.6 (clean install) - Mail 4.0 (64 bit) --> 4"
10.6 (upgrade from 10.5.8) - Mail 4.0 (64 bit) --> 5" (+20%)
10.5.8 - Mail 3.6 --> 6" (+33%)
10.5 (clean install) --> N/A
10.4.9 - Mail 3 --> 4" (0%)
iTunes (currently only available in 32 bit):
10.6 (clean install) - iTunes 8.2.1 (empty library) --> 5"
10.6 (upgrade from 10.5.8) - iTunes 8.2.1 (empty library) --> 5" (+20%)
10.5.8 - iTunes 7 (empty library) --> 9" (+44%)
10.5 (clean install) --> N/A
10.4.9 - iTunes 7 (empty library) --> 8" (+38%)
Firefox (currently available only in 32 bit):
10.6 (clean install) - FF 3.5.2 --> 6"
10.6 (upgrade from 10.5.8) - FF 3.5.2 --> 12" (+50%)
10.5.8 - FF 3.5.2 --> 13" (+54%)
10.5 - FF 3.5b4 --> 7" (+14%)
10.4.9 - FF 2.0.0.3 --> 7" (+14%)
iPhoto (currently available only in 32 bit):
10.6 (clean install) - iPhoto 7.1.5 (library with 1700+ pics) --> 5"
10.6 (upgrade from 10.5.8) - iPhoto 7.1.5 (library with 1700+ pics) --> 5" (0%)
10.5.8 - iPhoto 7.1.5 (library with 1700+ pics) --> 8" (+38%)
10.5 - iPhoto 7.1.5 (empty library) --> 2" (-150%)
10.4.9 - iPhoto 6 (library with 6700+ pics) --> 7" (+29%)
OpenOffice/Neoffice (currently available only in 32 bit; OpenOffice native versions not requiring X11 were not available until 1 year ago):
10.6 (clean install) - OpenOffice 3.1.0 --> 12"
10.6 (upgrade from 10.5.8) - OpenOffice 3.1.0 --> 15" (+20%)
10.5.8 - OpenOffice 3.1.0 --> 15" (+20%)
10.5 - OpenOffice 3.1.0 --> 13" (+8%)
10.4.9 - NeoOffice 2.1 Patch 1 --> 25" (+52%)
Safari (used only since the release of version 4.0):
10.6 (clean install) - Safari 4.0.3 (64 bit) --> 3"
10.6 (upgrade from 10.5.8) - Safari 4.0.3 (64 bit) --> 3" (0%)
10.5.8 - Safari 4.0.3 (32 bit) --> 6" (+50%)
10.5 - Safari 4 beta (build 5528.17) (32 bit) --> 1" (-200%)
Shutdown:
10.6 (clean install) --> 4"
10.6 (upgrade from 10.5.8) --> 5" (+20%)
10.5.8 --> 8" (+50%)
10.5 (clean install) --> 18" (+78%)
10.4.9 --> 19" (+79%)
Comments:
- Clearly a clean install is to be preferred to an upgrade install. The benefits of a freshly cleaned hard drive, with the apps and libraries, defragmented and all close to each other, does bring it's benefits. On average, the 10.6 clean install provided me with an additional 20% performance increase compared to the upgrade install measurements. Also the installation process is considerably shorter, 23' instead of 32' (30% less - but you still have to re-install everything though...).
- Memory usage: 10.6 has about the same footprint of 10.5.8, but strangely 20-30% more footprint compared to 10.5 and 10.4.9; 10.6 brings 64 bit & native multi-core support and several other improvements. Clearly the Intel architecture is extremely inefficient compared to PPC architectures, requiring more than 2x RAM after boot. With about the same RAM usage you get a system that is on average 40% faster than 10.5.8 and 30% faster than 10.4.9; on the same hardware!
- Regarding HDD usage, after the upgrade I had gained 3GB of free space; your mileage may vary, depending on installed applications and whether you are using Xslimmer or not. The System folder now is 200MB (-5%) smaller, the Library folder is 1 full GB smaller (-33%) and the user's library is 500MB less as well (-40%). Installing 10.6 is a no brainer in that sense.
- Booting is about 30% faster compared to Leopard; strangely no difference wrt 10.4.9. If you do a clean install, you get a 30% speed bump compared to the upgrade install.
- Shutting down is 50% to 80% faster. A clean install gives a 20% faster shutdown compared to an upgrade install.
- Regarding single applications loading times, wrt 10.5.8 there are benefits across the board, also on 32 bit applications, waiting for an upgrade to 64 bit. Notable examples are iTunes (20% to 40% faster), Firefox (20% to 50% faster; it has never been a lighting bolt...), iPhoto 7 (30% to 40% faster) and Openoffice (10% to 20% faster, but still stubbornly above 10" - about forever!); it would be interesting to see the performance of the 32 and 64 bit versions of a program side by side...
- Safari is weird: the current 64 bit version is yes, 50% faster than it's 32 bit counterpart, but 3x slower than the 32 bit beta that was available in 10.5.8 - why?
Bottom line: 10.6 from the outside doesn't seem to bring much - after reboot the only thing that gives a hint that you have upgraded is the new Aurora desktop wallpaper (more violet), the black pop-up menus for Dock Icons and a few other minor things here and there. But under the hood, there are major changes, last but not least, full multi-core management, 64 bit apps, cleaned up code (i.e. Finder). For 30$/€, with essentially the same RAM footprint you get more speed, faster booting and shutdown times and more hard drive free space.
Many applications are not yet optimized for multi-core processors and 64 bits, so the best is yet to come...
Apple again has managed to make a major transition seem effortless for the user. The OS, although at his first release shows, until now, some very minor bugs, but nothing that will not prevent you from working like you did before in 10.5.
It is true, 10.6 has booted the 32 bit kernel. I have tried to force it to 64 bit, but without success. But all applications and OS services that can run 64 bit, will do. The kernel runs currently, according to several sources outside of Apple, to guarantee the maximum compatibility with non 64 bit kernel extensions that will simply not work under a 64 bit kernel. Because the applications can and do instead fully work in 64 bit mode, there is no reason to panic. Likely in a couple of OS patches (i.e. 10.6.2) 64 bit kernel will be enabled, and probably the user will not even notice it.
Moreover if you have less than 4GB of RAM, right now there will be no additional benefit.
Interesting will be to see what 10.6 will bring to my Mac Mini running a Core Duo processor that does not support 64 bit processing. Will Grand Central Dispatch provide some benefit? Will I get more hard drive space?
More to come in the next few days, after the upgrade.