[ug-bosug] Nevada and x86 64bit CPU's : a few questions

[Manish Chakravarty]

Hi BOSUG,

I am looking for an Opteron based box with 8GB of RAM ( Saw one good
configuration for around 25k )

Since Nevada userland is 32bit, would it be able to address all of the 8GB
of RAM or like Windows XP , only the first 4GB will be used?

I know Ubuntu 64bit can access and utilize all of my 8 gigs if needed ( But
Ubuntu , like all 64 bit Linux distros has full 64bit userland).
I am confused because Nevada userland is 32 bit but the kernel is 64bit ( on
machines which have 64bit capable CPU's )

Two more questions:
1) How does this work? ( 64bit kernel and 32 bit userland; could some
explain in a little detail?)

2) Why does Nevada not ship with full 64bit userland?
I understand #2 would break binary compatibility for 32bit apps.

For this reason Ubuntu has the "ia32-libs" series of libraries.
For example VMWare Server for linux is a proprietary 32bit application.
When VMWare Server is installed (via apt-get) on a 64bit Ubuntu box,
"ia32-libs" , "ia32-libs-gtk" and other 32 bit libs are pulled in.
Ubuntu has a ton of these packages ( viz "ia32-sun-java" for one :) )

Could Nevada not have the same thing? Ship with a 64bit userland (for
performance) and 32 bit ( for backward binary compatibility )

Most (if not all ) Nevada users get software from source and compile it.
In such a case, they would be compiling straight to 64 bit. Not much of a
difference for them ( let them be using SFE or doing it by hand)
And they would end up using a full 64 bit system

-- Manish

-- 
Manish Chakravarty
http://manish-chaks.livejournal.com/
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