Just ordered a T61p from Lenovo with HUGE savings

[nurio]

The address space (4GB) split for 2GB application and 2GB for kernel is correct for 32 bit applications regardless of PAE. with the /3GB switch the that split changes to 3GB Application vs. 1GB Kernel and it is not always recommended, as the kernel space becomes more limited.
Here is a good article to read on this subject:
http://technet2.microsoft.com/windowsse ... x?mfr=true

[GarryF]

I know that the cost of Vistal Ultimate from Microsoft allows either 32 or 64 bit. I wonder if that is true for OEM Vista Ultimate.

I managed to install 64 bit on my new T61P, someone has written a small tool called ABR that backups your 32 bit vista key. You need a retail 64 bit disk, install vista then restore the key. I ended going back to 32 bit for the meantime, but it's good to know in a year or so time when things settle down I can go to 64 bit.

[erik]

The address space (4GB) split for 2GB application and 2GB for kernel is correct for 32 bit applications regardless of PAE.

that's correct, however the 3GB-to-4GB address space is only available on 32-bit OSs using /PAE and BIOSs supporting memory hoisting.   your average notebook BIOS running a 32-bit OS will not see 1GB of a 4GB total system without using the /PAE switch.

with the /3GB switch the that split changes to 3GB Application vs. 1GB Kernel and it is not always recommended, as the kernel space becomes more limited.
Here is a good article to read on this subject:
http://technet2.microsoft.com/windowsse ... x?mfr=true

the purpose to my post was simply to point out different ways the kernel can be split among a 4GB total system.   i'm well aware of what the /3GB switch does and its positives and negatives.   i read that very same article three years ago when i was debating between buying a T42p or building a desktop.   but, thanks anyway.