How much better are 64 but platforms

[Jamie Bowden]

On Wed, 29 Oct 2003, Bill Moran wrote:

> I understand that nobody can answer this question exactly, but I'm
> curious to hear people's experiences.  I mean, if you just took FreeBSD
> (for example) by itself and moved it from 32 - 64 bit, how much faster
> is it (assuming the same mhz processor, if possible).  How about
> PostgreSQL (which is the database server we're using).

I spend my days running SGIs, and I've got old Indys and Indigo2s on up to
current Origin systems here.  For code that REALLY needs 64bit, everything
obviously runs better on the 64bit clean platforms...but something we've
found is that for things that don't need 64bit, compiling it on 64bit
clean hardware runs it slower than the same code compiled on 32bit, and
then run on 64bit clean systems (I use an Origin300 2xR14000/600mHz for
tests).  This is code compiled using the same compilers, on the same
system, doing nothing more than changing Irix cc's options from:

-DEFAULT:abi=n32:isa=mips4:proc=r10k

to:

-DEFAULT:abi=n32:isa=mips3:proc=r4k

I have no idea if AMD/Intel systems will show this same sort of behaviour
or not.

Jamie Bowden

-- 
"It was half way to Rivendell when the drugs began to take hold"
Hunter S Tolkien "Fear and Loathing in Barad Dur"
Iain Bowen <alaric at alaric.org.uk>