Duane Rettig <email@example.com> wrote:
| >Frode Vatvedt Fjeld <firstname.lastname@example.org> writes:
| > Finally, assuming a 4GB address-space (see below),
| Minor correction: most current 32-bit operating systems only give you
| 2 Gb of usable space, though a couple of them can give you 3 Gb.
Yup. For example, see <URL:http://oss.sgi.com/projects/bigmem/> for the
the SGI "bigmem" patch for Linux, which supports up to 3.8 GB physical
memory on IA-32, providing up to 3GB user space. [That URL also contains
a discussion of the performance costs of "bigmem" on IA32, including such
things as forcing drivers to use "bounce buffers" & bcopy'ing to access
certain areas of memory.]
| > So I'm simply ignoring 64-bit architectures (for now).
| By the time you get to the point where you are ready to introduce
| your system to the world, even at worst case for the already late
| IA-64, the new 64-bit operating systems will be out and will fast
| become standard, and you will have latched on to the tail end of
| this 32-bit prevalence.
1. We (and others) have already publicly demonstrated large applications
(e.g., clustered HPC codes) running under IA-64 Linux.
2. Porting of Linux to AMD's "Sledgehammer" (64-bit extension to Athlon)
has already started. <URL:http://www.x86-64.org/>
So from what I can see, we'll be starting down the "tail end" of IA-32
by next summer!
Rob Warnock, 41L-955 email@example.com
Applied Networking http://reality.sgi.com/rpw3/
Silicon Graphics, Inc. Phone: 650-933-1673
1600 Amphitheatre Pkwy. PP-ASEL-IA
Mountain View, CA 94043