Python 2.5 WinXP AMD64

"Martin v. Löwis" martin at
Thu Sep 21 20:37:08 CEST 2006

Bjoern Schliessmann schrieb:
>> To be exact, you need a 64bit Windows OS on a 64bit cpu.
> Is there a reason that can be explained in a less-than-2-KB
> posting? :) I mean why Python depends on the processor type that
> much.

In the AMD-64 package, python.exe, python25.dll etc are declared
(by the linker) as binaries for the AMD64 architecture. If
you try to run such a binary on a 32-bit system, the operating
system will complain that it can't recognize the file type
(or that the architecture is wrong). Likewise for Itanium.

OTOH, Microsoft implemented an emulation mode for 32-bit
binaries on AMD64 and Itanium, so you can run the 32-bit
Python on Win64. On Itanium, this emulation has a significant
performance loss; on AMD64, the emulation is quite efficient
since the processor directly supports the emulation mode
(and better so than Itanium 1/2 did).


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