[floyd923]

Ok, so here is the noobish question of all, that I can't seem to get a straight answer. Is Core 2 Duo always a 64-bit processor? Or is there a 32bit version? I ask this because even the Intel site described C2D as being CAPABLE of 64 bit performance, never actually stating that it is a 64 bit processor.

Am I reading to much into this?



didn't know where to post this, so it ended up here....

[Jeff]

Core Duos are 32 bit and Core 2 Duos are 64 bit.

[kman445]

good answer jeff

[mac57]

The Core2Duo is a 64 bit chip. However, it can run in 32 bit mode, just like the 64 bit G5 chip can. Right now, Mac OS X Tiger 10.4.x is 32 bit software and so the Core2Duo runs in 32 bit mode. When Leopard comes out, which is reputed to support 64 bit, the Core2Duo should run in 64 bit mode.

So, in a sense the Core2Duo can be both, depending on the software it is running.

Anyone here old enough to remember the days of Windows 3.1, when the 32 bit extensions for Windows 95 started showing up early, and suddenly (gasp!) your Pentium would step up to 32 bits and run like a hot knife through butter (...well it seemed like that at the time anyway). I remember that my WFWG system suddenly seemed twice as fast when I installed the 32 bit file system and the other 32 bit extensions. It sure seemed fast at the time.

It is a similar idea to the Core2Duo. The early Pentiums were already 32 bit chips, but capable of running in 16 bit mode if presented with 16 bit software (Windows, DOS). But when presented with 32 bit software, they flipped to 32 bit mode and ran like crazy.

I understand that we wont see nearly the performance boost going from 32 to 64 that we saw going from 16 to 32, simply because CPU chips have been so optimized these days that it just doesn't make that much difference. I have read some articles that say that the G5 chips may even run a little slower when running in 64 bit mode! Sheesh!

[floyd923]

Thanks everyone for clearing this up.

Ah yes, I remember 3.1, I also remember Dos. But even before that I remember booting up in Basic! Sheesh, I am not that old am I?

10 PRINT "Hello Mac-Forums"
20 GOTO 10

[Amen-Moses]

Originally Posted by mac57

The Core2Duo is a 64 bit chip. However, it can run in 32 bit mode, just like the 64 bit G5 chip can. Right now, Mac OS X Tiger 10.4.x is 32 bit software and so the Core2Duo runs in 32 bit mode. When Leopard comes out, which is reputed to support 64 bit, the Core2Duo should run in 64 bit mode.

So, in a sense the Core2Duo can be both, depending on the software it is running.

Anyone here old enough to remember the days of Windows 3.1, when the 32 bit extensions for Windows 95 started showing up early, and suddenly (gasp!) your Pentium would step up to 32 bits and run like a hot knife through butter (...well it seemed like that at the time anyway). I remember that my WFWG system suddenly seemed twice as fast when I installed the 32 bit file system and the other 32 bit extensions. It sure seemed fast at the time.

It is a similar idea to the Core2Duo. The early Pentiums were already 32 bit chips, but capable of running in 16 bit mode if presented with 16 bit software (Windows, DOS). But when presented with 32 bit software, they flipped to 32 bit mode and ran like crazy.

I understand that we wont see nearly the performance boost going from 32 to 64 that we saw going from 16 to 32, simply because CPU chips have been so optimized these days that it just doesn't make that much difference. I have read some articles that say that the G5 chips may even run a little slower when running in 64 bit mode! Sheesh!

Tiger is partially 64 bit, i.e the underlying BSD Core (Darwin) is mostly 64 bit but the overlaying software (Aqua, apps etc) is 32 bit.

Leopard will be totally 64 bit (or at least everything Apple created will be) but will run all 32 bit stuff out there.

I'm old enough that when my PC owning buddies were going through the 8/16bit transition to some 32 bit apps I was quite happily using my fully 32 bit RiscOS system.

Mind you, prior to that I was using the 8/32 bit QL (8 bit system bus/32 bit processor) so I never quite understood their pain.

Last year I ran the 64 bit version of XP on and AMD PC and it was pretty cool, the only problem was that I could run basically one program that used the power, i.e the 64 bit version of Far Cry, but boy was it impressive!

Amen-Moses

[mac57]

I will hope that I may be as impressed by 64 bit software as I was when I first ran into 32 bit software. Back in the day, that was something. Here's hoping that 64 bit software can seem equally impressive!