Re: [RFT] Port 0x80 I/O speed

From: Edwin de Caluwé
Date: Wed Dec 12 2007 - 03:38:52 EST


Exactly constant timing in every iteration:

cycles: out 667, in 305

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 8
model name : Celeron (Coppermine)
stepping : 3
cpu MHz : 497.582
cache size : 128 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca
cmov pat pse36 mmx fxsr sse up
bogomips : 996.21
clflush size : 32


On 12/12/07, Paolo Ornati <ornati@xxxxxxxxxxxxx> wrote:
> On Wed, 12 Dec 2007 00:31:18 +0100
> Rene Herman <rene.herman@xxxxxxxxx> wrote:
> >
> > and on a PII 400 (Intel 440BX chipset) a constant:
> >
> > rene@6bap:~/src/port80$ su -c ./port80
> > cycles: out 553, in 251
> >
> > Results are (mostly) independent of compiler optimisation, but testing
> with
> > an -O2 compile should be most useful. Thanks!
> >
>
> ### Core2 Duo 1.8 GHz ###
>
> X86_64 -m32 -O2:
>
> $ for i in `seq 5`; do sudo ./port80; sleep 1; done
> cycles: out 1498, in 964
> cycles: out 1498, in 964
> cycles: out 1499, in 964
> cycles: out 1498, in 964
> cycles: out 1498, in 965
>
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 6
> model : 15
> model name : Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz
> stepping : 6
> cpu MHz : 1864.805
> cache size : 2048 KB
> physical id : 0
> siblings : 2
> core id : 0
> cpu cores : 2
> fpu : yes
> fpu_exception : yes
> cpuid level : 10
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
> pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm
> constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2
> ssse3 cx16 xtpr lahf_lm
> bogomips : 3731.82
> clflush size : 64
> cache_alignment : 64
> address sizes : 36 bits physical, 48 bits virtual
> power management:
>
> [...]
>
>
> --
> Paolo Ornati
> Linux 2.6.24-rc4-g94545bad on x86_64
> --
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