Could somebody explain the advantages or why I
would want to get a 64 bit cpu and motherboard.
I see AMD has them. My interest is that I want to build
a PC that will not be obsolete for as long as possible.
I understand that moving bigger chunks of data is faster.
But beyound that is this a fad or, in a few yrs. will 64 bit
be the norm.? What are the pros and cons of building a 64 bit
box today?
First of all, 64-bit computing requires 64-bit apps and a 64-bit OS.
Shortterm pros are that they are damn fast as 32-bit cpus as well, and
doesn't come at higher cost than Intel 32-bit topline.
And when WindowsXP86-64 and 64drivers become mature, you can possibly
play some 64games, like unreal3, in a not too far off future.
Cons are, that about that time, others will start to buy 64-bit
systems that are like 6 months more mature. My first 64-bit box will
be as cheap as I can get it. And it will be cheaper in 6 months.
If you choose to run a 64-bit OS, you can run 32-bit and 64-bit
applications. But not old 16-bit.
To run 16-bit applications on the Athlon64, you need to run a 32-bit
OS, which can't run 64-bit apps of course.
Why 64bit: Contrary to the natural assumptions of "bigger chunks of
data is faster", that is not it. That issue is already being dealt
with, from the original Pentium onwards. Our '32-bit' cpus already
have 64-bit data bus, and perform operations on up to 128 bit long
data in 128 bit wide registers (SSE2). And the Athlon64 still defaults
to 32-bit integers (since 32-bit is so useful). So understanding
64-bit in general terms of width, is misleading.
The 32-bit problem is the apps linear address space, which is limited
to (in Windows) 2GB. Removing this limitation, requires an entirely
new instruction set architecture, featuring longer (64) addressfield
for the instructions. Meaning a new cpu.
The longer address is the main thing. But since you're introducing a
new instruction set anyway, why don't do it differently, smarter, as
well? That's where a large part of the 64-bit performance increase
will come from. In 64-bit mode, the x86-64 has twice as many, twice as
wide registers as in 32-bit mode. Also, the cpus memory management,
converting virtual addresses to effective, is supposed to be faster.
ancra