ACPI slowing CPU... or something else
idmc_vivr at intgdev.com
Wed Jul 25 19:39:06 UTC 2007
I've two 5.4 desktop boxes. Pretty much the same installation; both
from the same CD, same apps, no monitor/keyboard, 1-user logged-on via
ssh (command-line only w/no gui) and otherwise lightly loaded.
Box_A: CPU: AMD-K7(tm) Processor (598.84-MHz 686-class CPU)
avail memory = 121630720 (115 MB)
ACPI disabled by blacklist.
Box_B: CPU: Intel(R) Pentium(R) 4 CPU 1.80GHz (1794.19-MHz 686-class CPU)
avail memory = 252186624 (240 MB)
cpu0: <ACPI CPU> on acpi0
acpi_throttle0: <ACPI CPU Throttling> on cpu0
When running the following segment of a small gawk program:
cnt=0; s=systime(); while(s==systime()) ; # next second
s=systime(); while(s==systime()) cnt++; # count for 1-sec
Box_A(600M) always reports 'cnt' between 310000 to 320000.
Box_B(1800M) has been as low as 167000 and never higher than 254000.
So -- Box_B is 3-times faster than Box_A but runs the segment (at
best) about 20% more slowly!
Yesterday was when I saw the Box_B(1800M) 167000-ish numbers. Today
after seeing an increase to the 250000-ish numbers, I started to
read-up on ACPI.
sysctl -a | grep cpu.*freq reports:
dev.cpu.0.freq_levels: 1796/-1 1571/-1 1347/-1 1122/-1 898/-1 \
673/-1 449/-1 224/-1
If I understand the 'sysctl' output, Box_B is running (now) at
1796-MHz. And for Box_B cnt==252433; for Box_A cnt==318942.
Any opinions on what's going on and/or what I'm not understanding?
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