4GB memory for Windows: just waste money?

[Lennart Sorensen]

On Tue, Sep 14, 2004 at 10:06:48AM -0700, Frank Peng wrote:
> I thought Windows is 32bit OS. So it should be using
> 4GB memory instead of you said 3GB memory.

Windows 32bit can give you a 4GB memory space, of which on most OSs the
top 1 or 2G is reserved for PCI mapping and the OS itself.  It can
actually access more than 4GB using a system called PAE which allows up
to 64GB.  You still only get 4GB memory space as far as an application
can tell, and it still is limited by what part of the 4GB memory space
the OS lets the application have.  It used to be 2GB application/2GB OS,
but most have switched to 3GB/1GB to let larger applications run.
basically you can run multiple applications on an 8GB machine with 32bit
windows and use 2 or 3GB per application, although you do get a small
performance hit when you pass 4GB since the system has to start using
memory mapping to get the ram above 4GB mapped into the lower 4GB (it
essentially swaps segments of memory in and out of the lower 4GB memory
space on the fly).  64bit windows (em64t/x86-64 compatible) can access
lots of ram directly and can give each application (64bit applications
that is) all the ram they want.

> If that is true, I should back off to INTEL 915P which
> has PCI Express port to drive ATI FIREGL V7100.
> 
> I know I should live with PNY FX3000/4000/3400. But
> look at the price, it kills me instantly. Should I
> live with 128MB PNY rather than 256MB ATI. They claim
> the 3D performance is 8.0GB/sec and it is certified
> with OPEN GL and DirectX9.0. ATI really scares?

In general ATI has slightly better Direct3D than nvidia, and nvidia has
better OpenGL than ATI.  And the price of a video card worries you while
you are looing at a Xeon?  What's the Xeon for?  The Xeon has larger
cache, slower ram (wby quite a bit) and costs a fortune.  Why would
anyone buy that?  Even the P4EE makes more sense than a Xeon for most
single cpu systems, and I don't even think that one makes much sense.
Have you looked at benchmarks of different cpus for the applications you
intend to run?  Is the Xeon good at that application?  Well i suppose
the PNY cards can be a bit expensive, although I thought some of the
lower end cards weren't that bad.

I hope PCIe becomes mature and available soon, because so far I am not
convinced it is ready yet.  Not enough decent motherboards and chipsets
with support for it.

> ATI is a Canadian company. I wish them make some
> money!

Well I have bought many cards from them.  I got sufficiently annoyed
when a 3 year old card could no longer get working drivers for Windows.
They have had badly broken driver releases for some cards for even
something as new as XP in the last few years.

Basically ATI has excelent hardware with lousy software support behind
it.

Just because they are Canadian doesn't mean they can get away with
providing users with junk.  It's not like Matrox is selling that much
lately either (lack of open soruce specs seems to be hurting some too).

Lennart Sorensen
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