I've read in various places that the latest developer releases of 10.6 boots a 32-bit kernel on all non-Xserve machines by default and that a certain key-combination during boot (or hacking) is required to load the 64-bit kernel. I've also heard speculation that certain older x86's won't even be supported by the 64-bit kernel.
I've got an older MBP (MacBookPro1,1) and I'm already seriously peeved that OpenCL isn't going to support my Radeon X1600; this would only be icing on the cake.
So, is this all stuff and nonsense...baseless speculation? I admit I'm not even entirely sure why some x86's would be supported and not others. Can anyone help?
release ... boots, not releases ... boots. Sorry; posted in a hurry.
All Macs with Intel processors will support Snow Leopard. Apple's first Intel-based Macs won't be able to support a 64-bit kernel or applications, however, because the Core Solo and Core Duo processors aren't 64-bit capable.
I haven't read anything about special key combos to boot to a 64-bit kernel, but the specifications on 10.6 Server indicate that if a machine is 64-bit capable and has at least 4GB of RAM, then a 64-bit kernel is automatically installed (and it doesn't have to be an XServe specifically; I could install 10.6 Server on my aluminum iMac with 4GB of RAM and get the 64-bit kernel).
MacBook 1,1 (the original) had a Core Duo processor -- which is 32-bit. I remember being peeved at the time that "wait a minute, the G5s are 64-bit, and we're going back to 32-bit?"
So *your* machine will never boot a 64-bit kernel. The processor simply won't support it. As for the Radeon X1600, I can't say for sure about it and OpenGL.
As for other machines booting 32-bit by default, I had not heard that. I thought SL was supposed to be 64-bit on all machines that support it.
i have a black core 2 duo macbook 2.4ghz w/ 2gb of ram. will this run 64 bit, or do i need 4gb.
So, here's the real deal on 64-bit and Snow Leopard:
--OS X has, for a while now, already been supporting 64-bit applications. Unlike with Windows, you can run 64-bit applications with a 32-bit kernel, and vice versa; the only limitation is that your kernel extensions have to be the same as the kernel, and your hardware (i.e. CPU) has to have a 64-bit instruction set.
--The big deal with 10.6 and 64-bit is that many basic functions of the OS, including the Finder, have been finally rewritten with 64-bit code (and were also optimized in the process). The 10.6 installation actually includes both 32- and 64-bit kernels, but by default, you'll be running the 32-bit kernel. This was done for compatibility reasons; a lot of 3rd party kernel extensions haven't been rewritten to include a 64-bit version, so installing a 64-bit kernel would break that application. (One such application that's currently limited in this way is VMWare Fusion.)
--The jury is still out on whether you can boot into the 64-bit kernel manually, or what hardware configurations will prompt the 64-bit version of the kernel to be loaded by default (with the client version of the OS, at least). 10.6 Server will automatically install and load the 64-bit kernel on machines that have 64-bit-capable CPUs and 4GB of RAM or more (cite: http://www.apple.com/server/macosx/technology/sixtyfour-bit.html).
--In general, the average home user will see virtually *no* performance increase with the new 64-bit code in 10.6. 64-bit isn't necessarily what makes a computer fast, clean code is. Apple has apparently worked very hard at cleaning up and optimizing code in the OS, and from a few scattered reports I've read from developers who have been using the prerelease versions of 10.6, it sounds like it's those optimizations that really make the OS scream.
Here's a good summary of how 64-bit will work with Snow Leopard:
so it won't matter, in fact might be better for normal use, if it is not the 64 bit kernel. i should spend my money on snow leopard, and not a ram upgrade (i only have enough extra money for one)
2GB of RAM will suit you just fine. Remember, OS X isn't the RAM hog that Vista/Windows 7 are...you don't need 4GB just to make the OS perform decently.
Heh, digging around I found this thread from 2006:
A couple prize nuggets from it:
Gentlemen, come claim your prize!
To tell the truth, I'm actually a little surprised that Apple has been as ruthless as they have been in consigning PowerPC to the dustbin of history. Well, maybe not "surprised", per se, but I... applaud their Machiavellian efficiency none the less.
Now if only I wasn't stuck with two perfectly good yet perfectly useless PowerBook G4s...
You could always send one to me. Will one of them run Classic, or boot into OS 9? I need a good SimCity 2000 machine.
Thanks for all the clarification. Focusing on the x86 thing I guess I overlooked the forest for the trees. That's what I get for going in over my head. It's kind of sad and irksome that I'm stuck in 32-bit land after spending almost $1000 on that thing last year, but from the sound of these posts I won't be missing out on quite as much as I thought.
I've installed 10.6, by the way, and it is faster in some respects. With my configuration (1.83 GHz 15" MBP upgraded to 2Gb RAM):
-The installation took something less than 30 minutes from an old USB 2.0 Firefly 20Gb drive that I restored an image of the install DVD to with Disk Utilty.
-It boots and wakes my 'Book from sleep more quickly than 10.5.8, as promised. It gets to the desktop faster, and whereas before it would take 15 or so seconds _after_ everything appeared on the desktop before everything became responsive, it's now pretty much ready to rock as soon as the desktop appears. It loads my widgets much more quickly, as well.
-It joins wireless networks more quickly.
-Initial launch after restart for some 3rd party apps, like those in the M$ O-Suite (2008) and some other various crap, is about the same as under 10.5.8, but subsequent launches are faster.
All anecdotal, I know, but if anybody is really curious I'll get out the stopwatch.
On the con side, Photoshop CS1 (8.0) occasionally crashes and chunks me out to the login screen. Of course it's really old and I don't think it's even universal binary, so I assume it's running under Rosetta (optional install.) I guess I will finally have to upgrade.
Overall, the upgrade was smooth and worthwhile. I haven't yet run into any problems other than the one concerning Photoshop.
P.S. I find the default desktop picture for 10.6, while still obnoxious, is slightly less abrasive than 10.5's. Just thought you'd like to know.
Dibs on the second one!
Har. I have plenty of young relatives to give them to and let them be torn up. (I actually had four of the bloody things before I started handing them out. And, yes, one keyboard has already been demolished by a three year old.) They're good platforms for those "Dora the Explorer"-type CD-ROM games you can find for 50 cents at the surplus computer places. ;^b
(Sad commentary for something that sold for two grand less then four years ago.)