Markgil, readyboost has nothing to do with what they're talking about.  I'm going to be as simple as I can in explaining this, but what it boils down (AKA: here is the over-simplified version for the computer illiterate) to is that 32 bit OS's are limited to 4GBs of memory total (specifically, 2 to the thirty-two bytes), and 64 bit OS's get a LOT MORE (2 to the sixty-four bytes).  Because of the way OS's work, you're actually limited to about 2GBs on the average 32 bit machine (note: you can still reap benifits from increasing memory to 3 or 4 GBs, this is an overly simplified explanation that doesn't really work right).

OK, time to mangle some computer science!

In the OS, you have to 'map' memory to memory spaces.  This is called allocation.  In a 32 bit system, you have 4GB 'address books' to address memory with -- so your system can have a total of 4GBs of memory installed.  If you install more, it gets ignored by the OS because it doesn't have the ability to 'map' all of it.  Note that peripheral devices with onboard memory (usually a video card, but some sound cards) count towards this limit -- if your video card has a half-gig of memory onboard, you can only have 3.5 GB or RAM for the OS.

*Program* side (here is what's important), you're also limited to 4GBs memory use per program.  You might off-load a lot of the 'memory' into virtual memory, but you can't have more than 4GBs of it in use.  Which sounds like a lot, except you (normally) only get half of this.  The other half* is held by the OS to use for drivers and stuff, leaving you with 2GBs to try and run the program with.  If you exceed those 2GBs, program goes 'boom' for excessive memory use.

*It is possible to move that divsion over using special commands in the boot-up sequences, but not recommended unless you're an expert.  It can cause system instability if a program or driver was programmed to assume that 2GB limit.  So they created a 'flag' for an executable file:  even if you've manually moved the partition over to 3GBs program space, it won't take effect on a given program unless it's flagged as being 'large address aware'.  Please note that this doesn't protect against bad drivers, that is your job if you try to do this.

Frogboy, are you aware that, because of your damn game, you'll just kill the 32bit OS? Hum. Who would have a 32bit OS when they can play A game of Elemental for 4 years because of the huge huge huge map?

June is so far away ...

And so companies make stable drivers for 64 bit too (I'm looking at you nvidia!)

I want a map that I can scroll across two 30" monitors at max resoultion. Please tell me multimon will be an inherent support element.

...

I spend something like 20 minutes trying to remember how to put it down simply, and you just come along and... and...

I don't know whether to hate you (for beingn so much better) or love you (for releasing games like elemental).

Just as computers 5 years ago couldn't approach the 4GB limit, computers these days won't come closer to touching the 64 bit memory limit -- sorry!

but hypothetically, when we have magical space computers that use something other than transistors because transistors have hit the limits of physical possibility, you could have a map about the same size as the contiguous US... in on-screen size, not display size, and have an accurate representation of a fantasy world the size of jupiter to scale that would take a few hundred years to play. And wouldn't that be worth it?

It'd be good publicity if you could make it a testing standard, just include a benchmarks section with the option to create a map the size of Rhode Island. The thing is, most 64-bit benchmarks are server ones much more representative of actual performance.

In all likelyhood, that data will get sucked away to things we don't actually make use off -- remembering where every single peasant was born, is, and will die is a lot of memory when you have an empire of 20 million souls.

(AKA:  Once it's available, we'll find ways to make (good) use of it.)

By the way, does anyone know if Windows 7 going to come standard as 64-bit?  Will it even come in 32-bit?

re: 18000 Petabytes; by the time that anyone can actually afford to make a computer with 1000+ Petabytes of RAM or a cpu-cluster can efficiently deal with such a large volume of data in a high-performance game... well, maybe we'll be storing the genome structures of all those peasants

with a 64 bit OS how big will tacticle battles be? around 5,000 units like total war? or 10,000 (in this case i will preorder immediatly)?

The thing about large troop numbers in tacticle battles is that it would depend more on your graphics card than just memory, but I suppose if you have 8+ gigs of RAM, then you probly will have a pretty sweet graphics card as well!

for the record, my PC is completely 64-bit ready but I have had no reason to upgrade my OS yet.  This would give me the reason to do it (if 64-bit is a go) and I would actually be greatful I think.