Re: Advantages of 64-bit vs 32-bit on old hardware

[Chris Ross <cross+netbsd%distal.com@localhost>]

On Wed, 2008-03-12 at 02:22 +0000, raymond.meyer%rambler.ru@localhost wrote:
> Do most people run NetBSD sparc64 on their UltraSparc hardware, or are there 
> people like me, who prefer NetBSD sparc (32-bit sun4u kernel + 32-bit 
> userland)?
> 
> I actually think that 64-bit binaries run slower on this platform. Ultra 10 
> has slow main memory, 50ns compared to modern DDR RAM, so the more 
> instructions that can fit into faster cache memory, the faster they will 
> execute. In fact smaller executables run faster, I build everything (kernel, 
> userland, pkgsrc programs, etc) with 'gcc -Os -mcpu=ultrasparc -mvis'

  To return this conversation back to the original software
question......

  I have a small number of Ultrasparc machines, older Ultra2's, an X1,
an AXi motherboard in a 2U case, and a recent acquisition of a e420R.
All of these are certainly sized to be *able* to run 64-bit
applications, but with the exception of the e420R, most of them have a
gig or less of memory, and are just servers.  Would there be a
performance benefit to running 32-bit userland, or the sparc port in
general, on them?

                                 - Chris