Re: CyrixInstead ?

Andrew Derrick Balsa (
Fri, 31 Jul 1998 10:56:30 +0000

Hello Nicolai,

> Hmmm, I've gotten a Cyrix 6x86 (IBM actually) and compiled kernels as
> Pentium/6x86 and never got my CPU identified correctly (unknown).

On 2.1.112 you can compile your kernel as a 386, 486, 586 or 686 and you
will still get correct identification of your Cyrix 6x86.
> Now I compiled (2.1.112) as 486 and voila,

Hmmm, you were probably using an older kernel previously. Note that the
recommended setting for the 6x86 is to compile as a Pentium, PPro or as
a last resort, as a 386. Compiling as a 486 diminishes kernel
performance because of the extra padding needed on 486-class CPUs.
> nicolai@nikita >>>
> /etc/X11 : cat /proc/cpuinfo
> processor : 0
> cpu family : 5
> model : 6x86 2x Core/Bus Clock
> vendor_id : CyrixInstead
> stepping : 2.7
> fdiv_bug : no
> hlt_bug : no
> sep_bug : no
> f00f_bug : no
> fpu : yes
> fpu_exception : yes
> cpuid level : 1
> wp : yes
> flags : fpu
> bogomips : 133.53

Looks OK to me. :-)
> Is this the desired behaviour? If yes, somebody should update the info in
> menuconfig and xconfig accordingly since it classes the 6x86 with the
> Pentium/K5/5x86 , which appears to be wrong...

This is the desired behaviour and the 6x86 is a Pentium class processor.
In fact at the same clock rate it provides roughly 10% better kernel
performance than a Pentium. Your 133MHz 6x86 is roughly equivalent to a
150MHz Pentium, in terms of kernel performance.

Please compile your 2.1.112 kernel as a Pentium processor and you will
notice the CPU is (correctly) identified as above. There is no need to
compile as a 486 (and it is not desirable either); the menuconfig and
xconfig information is correct.


Andrew D. Balsa

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