Intel abandons x86 emulation on Itanium

[Benjamin Gawert]

Intel scraps once-crucial Itanium feature | CNET News.com
http://news.com.com/Intel+scraps+once-crucial+Itanium+feature/2100-1006_3-6028817.html

Who cares? Windows on IA64 is basically dead, and for other operating
systems the x86 emulation layer simply is irrelevant. And even under
Windows the improved software emulation (WOW64, similar to that used to
run 32bit programs on x64 Windows) which arrived with Windowsxp
Professional 64bit Edition Version 2003 and the 2003 Server variant ran
circles around the hardware emulation, and for everything else there is
the IA32 execution layer software for Windows and Linux.

BTW: the x86 hardware emulation isn't completely dead, it moves into the
PAL (Processor Abstraction Layer) because it still is needed for EFI...

Benjamin

 

[Alex Johnson]

I remembered that Merced was the Intel design, while McKinley was the HP
design (yes, started in parallel).

Okay, enough misinformation. As Mr Kanter pointed out calling it the HP
and intel designs is an oversimplification (although the essence is
still true, the designs were heavily dominated by those companies). But
the real bug is everyone saying Merced and McKinley were "started in
parallel". McKinley was started 2+ years AFTER Merced. They
overlapped, but so do all products of generation N and N+1 at intel (and
AMD, IBM, SUN, Via, etc, etc, etc).

 

[Alex Johnson]

BTW: the x86 hardware emulation isn't completely dead, it moves into the
PAL (Processor Abstraction Layer) because it still is needed for EFI...

Benjamin

You are incorrect in saying it moves into PAL. PAL is firmware,
software very closely tied to the hardware. Hardware cannot be moved
into software and still be hardware.

Alex

 

[Benjamin Gawert]

You are incorrect in saying it moves into PAL. PAL is firmware,
software very closely tied to the hardware. Hardware cannot be moved
into software and still be hardware.

The functions of hardware can be done by software. But to be overly
correct I indeed should have said "the IA32 hardware emulation has been
replaced by software in PAL"...

Benjamin

 

[Benjamin Gawert]

I remembered that Merced was the Intel design, while McKinley was the HP
design (yes, started in parallel).

You remember wrong. Merced preceeded McKinley for over two years...

Benjamin

 

[George Macdonald]

Who cares? Windows on IA64 is basically dead, and for other operating
systems the x86 emulation layer simply is irrelevant. And even under
Windows the improved software emulation (WOW64, similar to that used to
run 32bit programs on x64 Windows) which arrived with Windowsxp
Professional 64bit Edition Version 2003 and the 2003 Server variant ran
circles around the hardware emulation, and for everything else there is
the IA32 execution layer software for Windows and Linux.

This seems a bit muddled to me: are you talking IA64 or x86-64 for the
"software emulation" of IA32? Just to be sure: for x86-64, obviously no
emulation is required to get IA32 - it's just a mode switch.

 

[Benjamin Gawert]

This seems a bit muddled to me: are you talking IA64 or x86-64 for the
"software emulation" of IA32?

Since this thread is about IA64 (Itanium) I thought it should be clear
that I'm talking about Itanium and not x64...

Just to be sure: for x86-64, obviously no
emulation is required to get IA32 - it's just a mode switch.

Somewhat correct. Yes, x64 doesn't need a software emulation since it
still can switch back to x86 compatibe mode. But no, there _is_ a
software emulation. It's called WOW64 and is included in the Windows x64
Editions, and it's used to run 32bit programs on the x64 processors in
x64 mode (because you can't run x64 processors in 64bit and x86 mode at
the same time). That's the same what has been used on IA64 with the
introduction of the Winxp Pro 64bit Edition Version 2003 (the 2001
version didn't had WOW64) and which was faster than the x86 hardware
emulation in the Itanium and Itanium2 processors...

Benjamin

 

[George Macdonald]

Since this thread is about IA64 (Itanium) I thought it should be clear
that I'm talking about Itanium and not x64...

And yet......

Somewhat correct. Yes, x64 doesn't need a software emulation since it
still can switch back to x86 compatibe mode. But no, there _is_ a
software emulation. It's called WOW64 and is included in the Windows x64
Editions, and it's used to run 32bit programs on the x64 processors in
x64 mode (because you can't run x64 processors in 64bit and x86 mode at
the same time).

Wrong - of course you can run x86-64 processors in 64-bit and 32-bit mode
at the same time. WOW64 in WinXP-64 for x86-64 is only something similar
to the thunking layer we used to have in 32/16-bit modes to interface to OS
& drivers - no software "emulation" required.

 

[Judd]

What are you getting so worked up over it for? So you figured out that
they were likely going to drop the x86 hardware support a long time ago,
congratulations this is your official proof that you were right.

Don't be a sourpuss Yousuf. You are generally on top of things. Just
surprised at your "surprise" of this announcement is all. I wasn't trying
to hurt your feelings.