I've been a bit slow answering this as I was meaning to do some tests of
my own, but as I haven't had the time...
As I understand it, one major factor is that a lot of motherboards only
cache a portion of the memory address space. Windows 95/98/ME have their
memory managed in such a way that if you put in more RAM than the cached
area code runs in uncached RAM.
This has the effect that applications slow down if you have too much RAM!
Of course this is offset by the increase in disc buffers and those apps
like Photoshop that need lots of RAM for data.
Windows NT and 2000 have a different layout of managed memory and tend to
keep code in low RAM.
Another non-intuitive situation is that increasing the RAM in W95/98/ME
doesn't have the slightest effect on the amount of resource space. So the
number of things you can run at the same time is unchanged no matter how
much RAM you have.
This is another limitation that doesn't exist in NT and Windows 2000. Each
process has its own resource space, so the number of concurrent processes
you can run depends upon the RAM size as well as the CPU power instead of
hitting a hard resource limit.
Add to that the ability to use multiple processors, each of which can
use an extra chunk of RAM, and NT and W2000 are inherently more powerful
when you start using lots of RAM.
bob@shomler.com (Bob Shomler) wrote:
> >2) It will use as much RAM as you can pack on a board. Windows 98 and
> ME >can't really use more RAM than about 256M effectively, but W2K can
> go all >the way :-)
>
> Can you elaborate on win98's inability to use larger RAM (or refer me
> to some discussion on this)?
>
> Thanks.
> --
> Bob Shomler
>
>
>
