Re: [gentoo-user] Gentoo 32bit->64bit: How?

[Florian Philipp]

Am 06.09.2010 19:27, schrieb meino.cramer@×××.de:
> Hi,
>
> My box is a working and fully configured Gentoo system, which is
> uptodate.
>
> For the sake of being able to address more RAM and for more
> calculation power (mainly for rendering purposes) I want to
> migrate to 64bit.
>
> I googled for some tutorial but found nothing appropiate (one post
> asked for the downtime to be expected while migrating a server --
> something which not applies to me...).
>
> My questions are:
> 1) Is there a performance gain, when migrating to 64bit if the
>    target applications supports 64bit?
> 2) Is it possible - if( true ){  how(); } - to """simply"""
>    "convert" a 32bit system to 64 bit.
>    "Simply" in my case means: Simpler ways than starting right
>    from the bare metal of a virgin harddisk and doing the same
>    stuff I did for the current system again... ;)
> 3) Is there some tutorial, which show me the path to go?
>

Concerning the performance gain:
Yes, there is. Besides all the improvements when dealing with data types
larger than 32bit you also gain a more general improvement:
More general usage registers on your CPU. That means less stress on
cache and RAM because more operands can be kept ready to usage. It also
speeds up function calls in general because a limited number of
parameters do not need to be passed by storing them on-stack but by
storing them in registers.

Converting:
Look at the mailing list archives. This question had been asked a number
of times over the last few years.

Hope this helps
Florian Philipp