Gentoo Archives: gentoo-sparc

From: Ciaran McCreesh <ciaranm@g.o>
To: "David F. Newman" <dnewman@×××××.com>
Cc: Josh Grebe <squash@g.o>, gentoo-sparc@l.g.o
Subject: Re: [gentoo-sparc] sparc64 userland
Date: Mon, 20 Sep 2004 18:34:39
Message-Id: 20040920193130.536387a3@snowdrop.home
In Reply to: Re: [gentoo-sparc] sparc64 userland by "David F. Newman"
On Mon, 20 Sep 2004 14:25:53 -0400 "David F. Newman" <dnewman@×××××.com>
wrote:
| No, I have no reason aside from pure geek value.  I was under the,
| probably false, impression that sparc64 executables could move data
| around faster.  i.e. doubles could be loaded in fewer clock cycles. 
| So I have 2 questions that maybe you can answer,
| 
| 1) Is the only advantage to a sparc64 executable access to memory
| larger than 2G per process?

Pretty much.

| 2) Assuming yes to question 1, then what is with the hype with 64bit
| processors?

x86/amd64 isn't like sparc/sparc64. amd64 CPUs are fast because they
have larger cache and a whole bunch of extra registers, not because
they're 64bit. On sparc, we can gain pretty much all the advantages of a
v9 CPU whilst still running a 32bit userland.

But then, "four times as many general purpose registers!" just doesn't
sound as cool as "64 bit!".

-- 
Ciaran McCreesh : Gentoo Developer (Sparc, MIPS, Vim, Fluxbox)
Mail            : ciaranm at gentoo.org
Web             : http://dev.gentoo.org/~ciaranm