Ubuntu 32 bits vs AMD64

[Vincent Arnoux]

Hi,

James Gray a écrit :

> Last Friday (14-Jul-2005) a thread titled "32/64bit ?" was started by
>
>"Bernie Betlach".  I wrote a fairly longish reply that answers most of your 
>questions and there were a number of other good replies.  To save you the 
>hassle, here's the link from the archives:
>
>http://lists.ubuntu.com/archives/ubuntu-users/2005-July/042359.html
>
>Gentle reminder: a LOT of good stuff is discussed on this list. Do a little 
>searching of the archives before posting because it's possibly been 
>answered before.  This saves you time, and us bandwidth :)
>
>Cheers,
>
>James
>  
>
Thanks you from your answer.
Actually, the points I am the most interested in were the two others 
your reply didn't answer ;) :

- Can I force my apt to look at 32 bits instead of 64 bits repositories ?
- I really need to use the 64 bits specificities of my CPU (for my professionnal apps), so can I somehow install Ubuntu 32 bits and "emulate" a 64 bits Linux without loosing too much performance (I heard about Xen...) ?

Vincent