Home Forums Mac Software Mac Operating Systems Enabling the 64-Bit Kernel

Hi all.

Per this Wikipedia page (under section 4.1 64-bit architecture ), on my machine, the 64-bit Kernel can be enabled by pressing the 4 and 6 keys during boot. It also said, I can permanently enable 64 by changing com.apple.Boot.plist.

I checked Profiler, but didn't see anything showing which kernel I'm using.

I tried the 4 6 keys, but wasn't sure if anything changed. Firefox did an upgrade when I launched it, so couldn't use that as a measure. iTunes seems to load at the same speed, but Britannica 2008 seems to load faster.

Three questions. How can I determine which kernel is running? Any pitfalls in changing kernels? And what in com.apple.Boot.plist do I change?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string></string>
</dict>
</plist>

Rather than trying to edit the plist directly, you can use the systemsetup command in Terminal, as per this archived Apple Support document.

Ok, great! I'll try that.

Does anyone else know how to determine which kernel is running?

Oh, that archived article answered that question.
Thanks again. In Profiler, it's under Software.

System Version: Mac OS X 10.6.8 (10K549)
Kernel Version: Darwin 10.8.0
Boot Volume: MacBook Pro HD
Boot Mode: Normal
Computer Name: MacBook Pro
User Name: Daddy
Secure Virtual Memory: Enabled
64-bit Kernel and Extensions: No (No means 32-bit kernel. Sorry if I'm stating the obvious.)
Time since boot: 12 minutes

After Restart I confirmed the system is now using the 64-bit kernel. So it seems to have worked, but the invalid connection or ports is a bit disconcerting. Any idea what this means and whether it's bad. This is the entire output of my Terminal session:

MacBook-Pro:~ Daddy$ sudo systemsetup -setkernelbootarchitecture x86_64

WARNING: Improper use of the sudo command could lead to data loss
or the deletion of important system files. Please double-check your
typing when using sudo. Type "man sudo" for more information.

To proceed, enter your password, or type Ctrl-C to abort.

Password:
setting kernel architecture to: x86_64
changes to kernel architecture have been saved.
MacBook-Pro:~ Daddy$ 2014-11-13 13:53:56.865 writeconfig[1249:903] *** -[NSMachPort handlePortMessage:]: dropping incoming DO message because the connection or ports are invalid

Here's what it did to com.apple.Boot.plist. Red lines are inserted text and the only change I am aware of.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Architecture</key>
<string>x86_64</string>
<key>Kernel Flags</key>
<string></string>
</dict>
</plist>

It's starting to feel like Christmas with these colors.

Has anyone found an answer to this?