Schizofrenie ve frekvenci CPU

[Jan Houstek]

HP Omnibook XE3 s procesorem Intel Pentium III (Mobile). Procesor je zda
se nejak schizofrenni, protoze obcas se hlasi jako 1133 MHz a obcas jako
730 MHz. Mozna je to zamer a ma to neco spolecneho s usporou energie, ale
moc nerozumim tomu, co vypisuje kernel:

# dmesg

Linux version 2.4.20 (root na utfnb1) (gcc version 2.95.4 20011002 (Debian prerelease)) #1 Po pro 16 00:11:47 CET 2002
[ ... ]
Kernel command line: auto BOOT_IMAGE=Linux_2.4.20 ro root=304
Local APIC disabled by BIOS -- reenabling.
Found and enabled local APIC!
Initializing CPU#0
Detected 730.910 MHz processor.
         ^^^^^^^^^^^
Console: colour VGA+ 80x25
Calibrating delay loop... 1458.17 BogoMIPS
[ ... ]
CPU: L1 I cache: 16K, L1 D cache: 16K
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
CPU:     After generic, caps: 0383fbff 00000000 00000000 00000000
CPU:             Common caps: 0383fbff 00000000 00000000 00000000
CPU: Intel(R) Pentium(R) III Mobile CPU      1133MHz stepping 01
                                             ^^^^^^^
Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Checking 'hlt' instruction... OK.
POSIX conformance testing by UNIFIX
enabled ExtINT on CPU#0
ESR value before enabling vector: 00000000
ESR value after enabling vector: 00000000
Using local APIC timer interrupts.
calibrating APIC timer ...
..... CPU clock speed is 730.9248 MHz.
                         ^^^^^^^^^^^^
..... host bus clock speed is 132.8952 MHz.
cpu: 0, clocks: 1328952, slice: 664476
CPU0<T0:1328944,T1:664464,D:4,S:664476,C:1328952>
[ ... ]


# cat /proc/cpuinfo 

processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 11
model name	: Intel(R) Pentium(R) III Mobile CPU      1133MHz
stepping	: 1
cpu MHz		: 730.910
cache size	: 32 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 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse
bogomips	: 1458.17


A po jednom rebootu:

# cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 11
model name	: Intel(R) Pentium(R) III Mobile CPU      1133MHz
stepping	: 1
cpu MHz		: 1129.596
cache size	: 32 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 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse
bogomips	: 2254.43

-- Honza Houstek