[filmscanners] Re: Digital Darkroom Computer Builders?

["Karl Schulmeisters" <karlsch@earthlink.net>]

Correct.

And Windows XP64 supports 64bit address space and runs in full Itanium 64bit
mode (ie the data path is 64bits wide), complete with handling all the Word,
Quadword and other alignment problems this raises.

It is true that many applications have not been re-written to take advantage
of the 64bit environment.  The few I have seen are a couple of CAD programs
and primarily database programs (because they want to have 'in memory'
databases).

It is absolutely incorrect to say that 32bit applications will not run on a
Windows 64 bit box.  I've seen it done.  And there are some benefits to
doing so:

Windows (for some fairly logical performance reasons) partitions 32bit
virtual address space into either 2Gb/2Gb or 3Gb/1Gb partitions between User
and OS address space.  This means that on a 32bit box, the most virtual
memory you can get allocated to User space (that includes application and
data) - is 3Gb.  On a Windows 64bit box, the OS is moved out of the lower 4
GBytes completley.  Allowing any 32bit application that is coded for it
(remmember app writers also make all sorts of assumptions about their memory
space), to use the full 4Gbytes.

Note that Photoshop does its own internal memory managment EVEN when it is
running on a platform like Windows XP which does a better job of memory mgmt
than Photoshop can.  This is because PS comes from the old AppleOs world
where if you let the OS do your mem-mgmt, you were pretty much dead in the
water.

As a result, unless you start PS with nothing else running, you will
actually be unable to access the full amount of memory you have.
Furthermore, if you do start to hit real-memory boundary limitations, the
swapping algorithms in PS will 'outthink' the virtual memory in Windows and
your performance will go into the toilet.

----- Original Message -----
From: "Austin Franklin" <austin@darkroom.com>
To: <karlsch@earthlink.net>
Sent: Wednesday, October 23, 2002 11:43 PM
Subject: [filmscanners] RE: Digital Darkroom Computer Builders?



Karl,

> Just to clear up some minor misconceptions

Yes ;-)

> Intel has been shipping "Itanium" chip sets for over a year now.  And
> Windows XP supports 64bit mode out of the box.

It may support a 64 bit address space, but that does not make it 64 bit
code.  Address space and processor instruction/data width are two entirely
different things.

Austin

----------------------------------------------------------------------------
------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title
or body

----------------------------------------------------------------------------------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe 
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or 
body