Recommendations...

[Jon 'maddog' Hall]

>I was thinking of Ubuntu 10.04.  My question is should I do 32 or 64
>bit?  If I go 32-bit I will not be able to use all the ram, and if I go
>64-bit I may not have all the drivers.

These days I would not worry too much between not having the proper
support for 64-bit Intel products over the 32-bit versions, as many
people now have 64-bit notebooks and desktops, and the vast majority of
the code you would need has been recompiled and tested for 64-bit.

But since you can pull down both versions of Ubuntu (32-bit and 64-bit)
for free and run them as a live-CD, you could test to see if the 64-bit
version had all of the device drivers for the Lenovo X61 before
installing it.

You may also want to test various plug-ins for Firefox, etc. although
most of the issues with those have also disappeared.

And even if you did the testing, then found out later that the 64-bit
drivers were "not up to snuff", if you separated your /home directory
from /, /boot, and swap you could easily switch back to Ubuntu 32-bit.

Or you could install a dual-boot or VMware version of the 32-bit code
for safety sake.

As to "not using all of your memory" with a 32-bit OS, I think you have
a misconception of how virtual vs real memory works.

It is true that a 32-bit machine can only access 4GB, and sometimes even
less than that (depending on how the application address space is
organized) in one *virtual* address space, but this does not necessarily
stop the kernel from "using all of RAM".  It is just that various parts
of multiple virtual address spaces get mapped into the physical memory
of the machine.  It was this concept that allowed the old PDP-11s, which
had only a 64K memory address space (128K with separate "instruction"
and "data" address spaces) utilize all of the physical memory on
machines that had multiple megabytes of RAM.

So even a "32-bit" OS could fully utilize the real memory of a 64-bit
CPU machine having multiple gigabytes of RAM if its memory management
software allows....it is just that the applications are limited to a
32-bit space at one time.

md