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

From: Maxim Levitsky
Date: Tue Dec 11 2007 - 19:15:08 EST


On Wednesday 12 December 2007 01:44:42 Rene Herman wrote:
> On 12-12-07 00:40, Maxim Levitsky wrote:
>
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1767, in 1147
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1774, in 1148
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1769, in 1150
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1769, in 1150
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1777, in 1150
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1766, in 1149
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1768, in 1148
> > maxim@MAIN:~/tmp$ sudo ./port800
> > cycles: out 1765, in 1147
> >
> >
> > Core 2 Duo system (ICH8/Intel DG965RY motherboard)
>
> 1.8 Ghz?
>
> Rene.
>
>

2.1 GHZ. but usually reduced by EIST to 1.5 GHz
(It can have just two values above)

I did the tests again:


CPU frequency locked to 2128.000 Mhz:
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1650, in 1065
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1648, in 1066
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1649, in 1065
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1648, in 1065
maxim@MAIN:~/tmp$


CPU frequency locked to: 1596.000 Mhz
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1730, in 1138
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1730, in 1138
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1735, in 1140
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1734, in 1139
maxim@MAIN:~/tmp$ sudo ./port800
cycles: out 1734, in 1138
maxim@MAIN:~/tmp$ 2128.000


A bit strange, isn't it?
Regards,
Maxim Levitsky
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