Dave said:
hi folks,
i'm currently running a Pentium-4 box with XP pro, and I'm looking at
upgrading my MOBO, ram etc to a 64-bit system.
some elementary questions: what does 64-bit apply to? I've been
recommended Intel i5 & i7 processors, on an asus board, is it the actual
MOBO that is 64-bit (and other hardware like RAM), or is it OS (win7) and
software that is 64-bit? I understand the 'bit' concept in terms of data
"pipelines" but I dont' know what exactly it applies to ... the architecture
of WHAT?
#2: if I upgrade my box to 64 bit MOBO / Win7 ... can I keep my same hard
drives, and perhaps install a dual-boot for WIN7 & WIN XP? I have a lot of
apps & data under XP and I can't afford to lose it. Does Win7 work in the
NTFS filesystem, which I use for XP? AND, in the other direction, will XP
run ok on this new 64 bit board (i5 or i7) ...?
thanks for adding any clarity ...
Dave
It's instruction width.
Instructions are executed inside the processor, so it is a processor property.
It might be referred to variously, as AMD64, EM64T, X86-64 and so on. An endless
stream of techy terms. Check the Intel or AMD sites, to get this information.
http://ark.intel.com/Product.aspx?id=35605&processor=E8600&spec-codes=SLB9L
Instruction set 64-bit
http://products.amd.com/en-us/DesktopCPUDetail.aspx?id=716
Operating Mode 32 Bit Yes
Operating Mode 64 Bit Yes
And in "Table 1. Processor operating modes" here, you can see that a
64 bit capable processor, has several operating modes. "Legacy Mode", allows
a 32 bit OS to be installed. "Long Mode" is for a 64 bit OS, and the
"Compatible mode" implies better backward compatibility.
http://www.codeproject.com/KB/system/AMD64_EM64T_architectur.aspx
As I understand it, 32 bit applications use WOW64 for compatibility on
a 64 bit Windows. But exactly how hard WOW64 has to work isn't clear.
http://en.wikipedia.org/wiki/WoW64
I've run into at least one case in Linux, where you can set up a
"pure" 64 bit mode, implying they're using Long Mode/64-Bit mode.
On that particular OS, if you download some 32 bit code (like
Adobe Flash was limited to at one time), it wouldn't run. So it is
possible to set up things in a very exclusionary way, if you want.
But for the time being, there is still compatibility, as it doesn't
make sense to toss away all those 32 bit applications on a whim.
And that means 64 bit OSes will continue to offer to run 32 bit
applications for you (Windows or Linux).
*******
You need a motherboard that can take your new processor. As long as the
processor is in the "supported" list, that's what counts.
If you go to the motherboard manufacturer site, look under "Downloads", and
check the OS menu there, you're likely to see at least WinXP listed. There
is no reason to remove it quite yet. (Win2K is another matter.)
A motherboard manufacturer sells more motherboards, if they support
a few more OS possibilities.
*******
Windows 7 offers "WinXP Mode", which is a copy of WinXP running within
a virtual machine, relying on Terminal Services to pop up a window and
display the results on the Windows 7 desktop. That is different than
just running an application in some "compatibility" mode, because
the application would be fooled into thinking it's in a real WinXP
environment. The only thing that wouldn't work there, is say
a program that diddles hardware directly - a virtual machine
environment can be poor for things like that (because hardware
can be emulated and not real). Virtual machines are great for
applications that "just like to compute".
"WinXP Mode" is only offered on certain versions of Windows 7,
It's so Microsoft can double their income. This is mainly for
people like me, who buy a laptop, get a lowly version of Windows 7,
which would force me to buy an "Any Time Upgrade", to upgrade my
OS so WinXP Mode would work. So for people who buy pre-built computers
(Dell/HP etc), chances are you'd be paying an extra fee to get
WinXP Mode running. But it wouldn't be much work to do it, just money.
http://en.wikipedia.org/wiki/Windows_xp_mode#Windows_XP_Mode
"Applications running in Windows XP mode do not have compatibility issues,
as they are actually running inside a Windows XP virtual machine and
redirected using RDP to the Windows 7 host. For 64-bit editions of Windows 7,
XP Mode may be used to run 16-bit applications; it includes NTVDM.
Windows XP Mode is available free of charge to users of Windows 7 Professional,
Enterprise, and Ultimate. Users of other editions of Windows 7 are
not eligible to download and use it. This restriction does not
apply to Windows Virtual PC itself."
HTH,
Paul