TestMac.net has published a quick look at Mac OS X Snow Leopard. “The biggest changes are under the hood. Snow Leopard is fast. Very fast. Like, surprisingly fast. From boot times to general application usage, Snow Leopard was noticeably quicker then Leopard when using the same system. Apple and 3rd party applications alike, they all launched faster and performed smoother. I’m sure this can be attributed to the new 64-bit architecture, but its amazing how much of a difference it really is.” Screenshots included.
Haven’t heard this one before.
Edited 2008-06-26 23:22 UTC
I wonder if they simply imported a lot of the changes from freebsd 7, or if that is even possible now with their darwin kernel?
Darwin has another kernel, xnu, which is quite different. MacOS X isn’t FreeBSD + stuff, it’s Darwin + stuff, and my guess is that even though they use some stuff from FreeBSD it’s not really something that would give such a speed-up.
My guess is that the speed comes from the jump to 64-bit (more registers etc) and optimizations. Which is great news indeed. What I do wonder is if they are using some cool SSE(1-4) voodoo as well:) Nice not having to focus on old CPUs
If you want to know about how OS X is really constructed, there is a an *awesome* video recording from the 24C3 hacker meeting. You can find it under:
http://chaosradio.ccc.de/24c3_m4v_2303.html
IIRC XNU even stands for Xnu is Not Unix.
Most of OSX’s FreeBSD bits are userland, not kernel.
well yes but code from freebsd still is an important part of the kernel. if i remember correctly, originally a big part of the freebsd kernel was bolted on top of mach and combined with the driver subsystem io-kit. that’s why the bad multithreading support of bsd affected xnu too. most programms don’t call mach directly but through bsd-threads.
but i have no idea how much room for improvement is left and if the improvements of freebsd 7 are of any use for xnu. if they happened in a part of the kernel covered by mach, they aren’t. but i think that the bsd-part also provided the posix threading model and that has been improved in freebsd 7. apple syncronised the bsd-part of xnu with freebsd 5 in darwin 7 (osx 10.3).
ps:
http://www.osnews.com/thread?283223
pss: http://www.kernelthread.com/mac/osx/arch_xnu.html
Edited 2008-06-27 16:34 UTC
There are a number of operating systems that offer 32bit and 64bit versions: XP, Linux, etc.
So as OSX makes the transition and speeds up; it leaves the question – does OSX speed up by a greater or lesser factor compared to other operating systems doing the same transition?
There is room for a good article on this: pinning down the practical performance enhancement of moving from 32bit to 64bit operating systems; and suggesting which O/S are on the curve and which are behind it.
Leopard (10.5) already supports 64 bit programs. I suspect the article is confused, perhaps by rumors that Snow Leopard was only to run on 64 bit processors. The main processing advances in Snow Leopard are for additional multiple core performance for applications (Grand Central), and offloading some mathematical operations onto GPUs (OpenCL).
Tests I’ve seen all conclude that MacOS is completely focused on the desktop experience, server benchmarks are terrible. Since they have (way overpriced) rack servers, I wonder if they address this at least a little bit.
if the code from freebsd 5 is to blame and they switch to freebsd 7, that might change the picture quite dramatically:
http://people.freebsd.org/%7Ekris/scaling/mysql-freebsd.png
http://people.freebsd.org/%7Ekris/scaling/os-mysql.png