Word look alike?

In article , Paul
wrote:


That doesn't mean the 32-bit version is slower. It does mean
you can't open documents bigger than 4 GB;

32-bit does not mean that.

usually it does, often 2-3 gb due to os limitations, but not always.

Without dwelling on detail, 32-bit Photoshop could
malloc around 1.8GB of memory.

you mean skipping detail.

32 bit photoshop on windows can address 2gb of physical memory, 3gb
with the /3gb switch and ~3.5gb on mac.

photoshop also implements its own virtual memory system which can go
beyond the 32 bit address space limit of 4gb, up to a theoretical limit
of 4 exabytes for photoshop 7 (20 years old).

If Photoshop had multiple
undo buffers,

it does, and has since version 5, nearly 25 years ago.

then the uncompressed size of images in
memory could be "relatively small" by modern standards.
The 1.8GB value was related to the 2GGB:2GB address
space split, with 2GB for kernel addresses and 2GB for
user-space addresses. And the malloc of memory for the
program is in user space, and in that example, can't be
more than 2GB. And for Photoshop, this number happened
to be 1.8GB. We don't really know what filesizes might
correspond to the availability of that much RAM.
Maybe a 2MB GIF decompresses to fill a 1.8GB space
in memory for example.

no.