Probably the main reason Intel didn't bother including this support in
the desktop boards is that current non-server versions of Windows (at
least 32-bit) won't use any memory that is mapped above 4GB anyway even
though PAE is enabled - a purely artificial limit that MS put in place
to discourage using desktop Windows on such large memory machines..
Agreed -- I _was_ going to inquire about XP x64 versions, and PAE also,
and I've read a bit about it (as microshaft has written on it's site),
but not in quite a while. I recall the semi-related NoExec (NX) bit
stuff (though I forgot the mnemonic difference between AMD64 and Intel
concerning this "bit", which if set disallows execution of any code
above the 4GB boundary, IIRC).
to follow-up: Do the XP x64 versions do something else artificially to
enable addressing up to 16GB of RAM or thereabouts. Or - is it that PAE
(Physical Address Extensions) stuff again that allows or it?
More importantly -- I have (an as-yet-to-be-assembled system) : AMD64
s754 3000+ with a crappy mATX mobo here (VIA KTm800/8237) Chipset --
The RAM limit is 2GB total (2 x 1GB DIMM slots only). Do you think this
el-cheapo mobo would have problems accessing over 4GB *if* the Mobo was
designed for 4GB ?? IOW-- a Mobo perhaps such as General S uses (MSI,
ASUStek, etc) -- or do you know if there's something different between
the s754 and s939 models that I'm unaware of (besides the No Dual
Channel RAM in s754, since it's only 64bit Single-Channel capable, not
128bit).
Thanks for the continuing discussion -- I'm glad I didn't follow Intel
recently and become deceived again - as I'm sure MANY have -- you'd
think buying a spanking new Pentium-D (8xx) and a 'decent' Intel
Desktop mobo would allow access to more than 4GB RAM ...but no.... :-(
(especially when the specs for the mobo claim "4GB" - heck - might as
well remove 1 x 1GB DIMM, you'd only lose 200MB (yikes)).