Where to find if a Mac Pro is 32 or 64 bit?

If you go to the Everymac site and look up that machine it says that it is 64-bit.

The processor of course is. But the OS was not always full 64-bit, and yours will not enable 64-bit kernel but it can run 64-bit apps, lacking the memory benefit of the 64-bit kernel and lacking ability to install and use 10.8

The G5 was "'sort of 64-bit" but not fully, the registers were not 64-bit. The OS of course was not using 64-bit words and instructions.

A Mac OS X has been able to use up to 48GB RAM and with Snow Leopard and later that was increased to 96GB and 10.8 will allow up to 128GB RAM.

So unless you need the 15% booost in performance of 64-bit kernel, if you needed support for more than 32GB RAM which is the max you can physically use, you don't need 64-bit kernel. Whether you need Lion or later like Mountain Lion is up to you.

Snow Leopard was the first OS X that was a full 64-bit OS and you had 32-bit and 64-bit drivers, and issues. And the 2010 Mac Pro 5,1 was the first to default to boot 64-bit mode. 2009 with SL could be set to use the 64-bit kernel.

A little background

http://www.macperformanceguide.com/SnowLeopard-64bit.html

I'm sure you could find an article on www.wikipedia.com

----

you cannot change the EFI firmware. That controls whether it can use 64-bit kernel (it cannot, that code that ws in ML DP1 vanished).

You only needed Snow Leopard to have a 64-bit OS. ie, you can boot using a 32-bit kernel and still run 64-bit applications on top of it.

What you cannot do is assign more than 4GB to a process or thread or application which can help handle larger portions of memory on large data sets or files.

2008 and later modes has EFI64, an Apple derivative of UEFI specification. Those support 64-bit mode.

If you read the Apple articles on this subject, they assure you that you have a 64-bit processor. But that is not really the question most Users are really asking.

The real question is, "am I running the best and fastest and most memory and future-proof?"

The answer for Macs issued before 2008 is unfortunately, NO.

You cannot run 64-bit Kernel, which contains the 64-bit memory allocator, so you cannot address more than 4GB in any single Application.

Although it is not certain, many expect that 10.8 Mountain Lion will be inaccessible to Macs issued before 2008.

Dual boot. Keep Snow Leopard for when you work, and Lion for play.

iLion does not roar, it is a kitty with the iOS ification for devices come to desktop and most people like the iPhone or iPod and ease of feeling at home.

wait 6-12 months for ML to have legs. Wait for the 2013's if / when etc.

The only thing ML might have of real value to some is support for a GTX 680, nothing else.

This is what happens though when you tie the OS and hardware in a strangle hold. You can't use GTX 570 w/o 10.7.4 for one thing.

ps: I think Grant writes clear easy to read. I have that "b" and "d" use to look same or couldn't be sure syndrome when I was learning, and I still have to rewrite and rearrange when I try to write.

I did not relish Google but after itunes 10.5 to get iOS 5 and the small screen iPod Touch I went to Android tablet. I prefer Google over iSync - even if there were not the issues with duplicates and issues with contacts and address books and Apple ID.

And I don't need to change OS though I will not install iTunes anymore on Windows except as a VM or something or that I only run (dual boot) IF I run into needing to (cannot imagine that happening).

3 could be split and clone partitions of each OS

4 for TimeM

2 for data

1 for both OS

lower optical drive bay SSD for your favorite OS

Thought CS5 works but CS3 is trouble??

your mac runs 10.4.7+

ML? so it is tird into???

value now won't change it already has sat at$600-800

ASAP? please

wait six months AFTER the magic ru,ored "2013's" come out

pck up a cheap macbook air or pro refurbished if you find you have tjis addiction to the latest hyped product marketing