config.guess returns wrong CPU

[rogue at wi.rr.com]

I don't think this is really a GMP bug, but I don't where else to post this.

I have 2 P4s at my disposal, one a Dell desktop, the other an HP laptop
(the model is Compaq nc8230).  config.guess returns pentium4 for the
Dell, which is obviously correct, but on the HP, it returns pentium3. 
GMP still builds correctly on the HP, but without any P4 optimizations.
 I can build GMP on HP by changing config.guess to return pentium4 and
it does build correctly and pass all tests, but I would like to
understand why it returns the wrong CPU type.  I was hoping someone on
this list could help me out.

I was able to track the difference down to config.guess.  On the Dell,
the returned value from the call to cpuid is "f29".  On the HP, it is "6d8".

Both machines are using the latest version of Cygwin, gcc, and GMP.

configfsf.guess returns i686-pc-cygwin for both PCs.

uname -a returns the same values for both (outside of the machine name:
CYGWIN_NT-5.1 MKE01886 1.5.24(0.156/4/2) 2007-01-31 10:57 i686 Cygwin
CYGWIN_NT-5.1 MKE06268 1.5.24(0.156/4/2) 2007-01-31 10:57 i686 Cygwin

The gcc version (on both machines) is:
Reading specs from /usr/lib/gcc/i686-pc-cygwin/3.4.4/specs
Configured with:
/usr/build/package/orig/test.respin/gcc-3.4.4-3/configure --verbose
--prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib
--libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info
--enable-languages=c,ada,c++,d,f77,pascal,java,objc --enable-nls
--without-included-gettext --enable-version-specific-runtime-libs
--without-x --enable-libgcj --disable-java-awt --with-system-zlib
--enable-interpreter --disable-libgcj-debug --enable-threads=posix
--enable-java-gc=boehm --disable-win32-registry --enable-sjlj-exceptions
--enable-hash-synchronization --enable-libstdcxx-debug
Thread model: posix
gcc version 3.4.4 (cygming special, gdc 0.12, using dmd 0.125)

Does anyone have a clue as to why this is happening?

--Mark