Linked by Thom Holwerda on Thu 26th Jun 2008 21:52 UTC, submitted by Taylor
Mac OS X 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.
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I wonder
by airwedge1 on Fri 27th Jun 2008 05:09 UTC
airwedge1
Member since:
2006-02-22

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?

Reply Score: 1

RE: I wonder
by John.Gustafsson on Fri 27th Jun 2008 09:18 in reply to "I wonder"
John.Gustafsson Member since:
2005-08-08

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 ;)

Reply Parent Score: 2

RE[2]: I wonder
by Alleister on Sun 29th Jun 2008 12:51 in reply to "RE: I wonder"
Alleister Member since:
2006-05-29

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.

Reply Parent Score: 2

RE: I wonder
by anevilyak on Fri 27th Jun 2008 13:01 in reply to "I wonder"
anevilyak Member since:
2005-09-14

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?


Most of OSX's FreeBSD bits are userland, not kernel.

Reply Parent Score: 2

RE[2]: I wonder
by puenktchen on Fri 27th Jun 2008 16:24 in reply to "RE: I wonder"
puenktchen Member since:
2007-07-27

"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?


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:
Here's an interesting statistic, the /bsd folder of the XNU kernel tar ball accounts for 49.2% of the untarred size on disk.

http://www.osnews.com/thread?283223

pss: http://www.kernelthread.com/mac/osx/arch_xnu.html

Edited 2008-06-27 16:34 UTC

Reply Parent Score: 1