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64-bit question

A

akadmon

Suspended
Original poster
Aug 30, 2006
2,006
2
New England
In the Info dialog for any 64-bit capable app in SL (e.g. Safari) there is a new check box "Open in 32-bit mode". Does checking this off make any difference when the machine is booted in 32-bit mode to begin with (system default)? In other words, do 64-bit apps always run in 64-bit mode no matter what mode you boot the machine in, unless this box is checked off.

I'm asking because I was having a problem with the 1Password extension for Safari (the 1P icon would not show up on the toolbar), which went away after I forced Safari to open in 32-bit mode, despite the fact that my machine was not booted in 64-bit mode (heck, it's not even supposed be 64-bit enabled, it being a 1st gen Mac Pro).

Hm...
 
The apps run in 64-bit even if the kernel (booting the machine) is 32-bit.

The reason 1Password didn't work is because only the 3.0 beta is SL compatible.
 
So why would anyone need/want to boot in 64-bit kernel, if the 64-bit apps run in 64-bit mode all the time and the 32-bit apps are potentially unstable when the machine is booted in 64?
 
It only has to do with which binary of the application is loaded - 32 or 64 bit. The option is there for the very issue you've discovered. 1Password hasn't yet released a 64-bit version of its app. Since it's an all or nothing proposition, 64-bit Safari can't load 32-bit 1Password. I have the same problem with Cosmopod (they're working on the 64-bit release).

Anyway, the short(er) answer is: switching Safari to 32-bit might allow 1Password to load (providing there aren't other SL incompatibilities). You'll have a bit of performance hit in Safari, but you'll be up and running. I imagine the 1Password folks will have an update very soon, though. They seem to always be right on top of things.
 
akadmon said:
So why would anyone need/want to boot in 64-bit kernel, if the 64-bit apps run in 64-bit mode all the time and the 32-bit apps are potentially unstable when the machine is booted in 64?
Click to expand...

Using 32-bit or 64-bit apps is a totally separate issue from a 32 vs. 64 bit kernel. The compatibility issues arising from using a 64-bit kernel are due to the same conflict 1Password has: a 64-bit kernel can't load 32-bit kexts. Since there aren't replacements for most 3rd party kexts, yet, it makes no sense to boot into 64-bit mode. Also, the vast majority of users will not see any performance increase from using a 64-bit kernel (that's been covered in many other threads/articles/forums).
 
akadmon said:
So why would anyone need/want to boot in 64-bit kernel, if the 64-bit apps run in 64-bit mode all the time and the 32-bit apps are potentially unstable when the machine is booted in 64?
Click to expand...

Booting a 64-bit kernel allows individual apps to address more than 4GB of RAM, as well as 64-bit drivers. There is little advantage to it at this moment, but in a year or so, 64-bit will be standard.
 
r.j.s said:
Booting a 64-bit kernel allows individual apps to address more than 4GB of RAM, as well as 64-bit drivers. There is little advantage to it at this moment, but in a year or so, 64-bit will be standard.
Click to expand...

It just allows the kernel to address > 4GB RAM. Apps can do this (and could in Leopard) regardless of the kernel mode.
 
akadmon said:
So why would anyone need/want to boot in 64-bit kernel, if the 64-bit apps run in 64-bit mode all the time and the 32-bit apps are potentially unstable when the machine is booted in 64?
Click to expand...

It's for if the kernel itself needs to address more than 4 gb of memory. This isn't an immediate requirement, but when RAM requirements get huge (<100 gb) the RAM won't be able to be addressed by the kernel in a 4gb space.

Full explanation here: http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars/5
 
Thanks. Btw, you're not slow. Anybody who can use kexts in a coherent sentence is not slow. And no, I will not embarrass myself by asking another question (what the hell is a kext?).:)
 
darkcanuck said:
It's for if the kernel itself needs to address more than 4 gb of memory. This isn't an immediate requirement, but when RAM requirements get huge (<100 gb) the RAM won't be able to be addressed by the kernel in a 4gb space.
Click to expand...
This is totally correct (and the Ars link is a most interesting read!). In essence, 64-bit kernel is mostly there for forward compatibility. It's not much use currently (though may have some benefits on current extremely high end servers), particularly for the machines that cannot even boot the 64-bit kernel (due to firmware or driver incompatibilities).

It's also very good for testing for developers and Apple itself to keep moving forward, given that 64-bit is the future. It's not an overnight transition, but Snow Leopard was a large step towards it.
 
akadmon said:
Thanks. Btw, you're not slow. Anybody who can use kexts in a coherent sentence is not slow. And no, I will not embarrass myself by asking another question (what the hell is a kext?).:)
Click to expand...

Not a problem at all :)

kext = kernel extension

I was being lazy - anyway, kext is more fun to type. ;)
 
gr8tfly said:
It just allows the kernel to address > 4GB RAM. Apps can do this (and could in Leopard) regardless of the kernel mode.
Click to expand...

darkcanuck said:
It's for if the kernel itself needs to address more than 4 gb of memory. This isn't an immediate requirement, but when RAM requirements get huge (<100 gb) the RAM won't be able to be addressed by the kernel in a 4gb space.

Full explanation here: http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars/5
Click to expand...

Whoops. You're right.
 
I strongly encourage everyone to read that article over at ars linked to above. All 23 pages. I consider myself pretty technical, yet I still only understood about 75% of it, but what I did get answered so many questions about why 10.6 is what it is. More importantly, what it means for us in the future once developers start taking advantage of it.

Awesome read.

http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars
 
CIA said:
I strongly encourage everyone to read that article over at ars linked to above. All 23 pages. I consider myself pretty technical, yet I still only understood about 75% of it, but what I did get answered so many questions about why 10.6 is what it is. More importantly, what it means for us in the future once developers start taking advantage of it.

Awesome read.

http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars
Click to expand...

I thoroughly enjoyed it, especially the low level goodies. I'm a engineer, so I already had a pretty good idea of the significance of the technologies released with 10.6. But, after reading this article, I came away with even more appreciation for all their hard work. Anyone who thinks Snow Leopard is a minor update or a "10.5 patch" needs to read this.
 
gr8tfly said:
kext = kernel extension
Click to expand...


That's what I thought, though the first image that the expression brings to (my) mind is that of a corn head with those persistent little tufts sticking out the top. Now lest you think I'm a total ignoramus, I have heard about kernel panics, and had one or two of those in the 3 years since I got my MP. I do often wonder why some people refer to them as "karnal panics" on this board. Truth be told, I find this extremely annoying! It reminds me of my first (not so successful) sexual encounter ;)
 
darkcanuck said:
It's for if the kernel itself needs to address more than 4 gb of memory. This isn't an immediate requirement, but when RAM requirements get huge (<100 gb) the RAM won't be able to be addressed by the kernel in a 4gb space.

Full explanation here: http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars/5
Click to expand...

Actually, it is for the kernel to address more than 32GB of RAM. OSX uses the PAE feature of CPUs introduced with the Pentium Pro, later sold as the Pentium II. Ya know, that same CPU that was scorched by the blazing fast G3.

http://www.youtube.com/watch?v=Cz78v4euRd0

http://www.youtube.com/watch?v=zE6aKeK61A4&feature=related
 
gr8tfly said:
Anyway, the short(er) answer is: switching Safari to 32-bit might allow 1Password to load (providing there aren't other SL incompatibilities).
Click to expand...


I switched to 32-bit Safari and still had the same problem (1P tool icon does not show up in toolbar) so I'm guessing there are other incompatibilities.
 
Van W said:
I switched to 32-bit Safari and still had the same problem (1P tool icon does not show up in toolbar) so I'm guessing there are other incompatibilities.
Click to expand...

Did you install the 3.0 Beta of 1Password? You need that, the older versions don't work with SL.
 
r.j.s said:
Did you install the 3.0 Beta of 1Password? You need that, the older versions don't work with SL.
Click to expand...

I did not because the documentation said that Version 2 would work as long as 32-bit mode was turned on.

Unless there is another trick, I guess I'll just get 3.0 Beta.
 
Amdahl said:
Actually, it is for the kernel to address more than 32GB of RAM. OSX uses the PAE feature of CPUs introduced with the Pentium Pro, later sold as the Pentium II.
Click to expand...

No, a 32-bit kernel, PAE or not, cannot address more than 4GB of memory. No single process can address more than 32-bits of address space. The kernel is a single process. The OS, as a whole, can utilize more than 4GB because of PAE.

S=
 
akadmon said:
Not true. I and running Password 2.9.31 (build 7574) on SL, with Safari set to open in 32-bit mode.
Click to expand...

Just to share, 1P 3.0 is sooo nice. :cool: I haven't had an issue with logins or anything. I'm not the strongest user of it but it hasn't given me an issue so far.
 
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