[ltp] hdparm settings?

[Alejandro Bonilla]

Nathan Kurz wrote:

>On Sat, Feb 19, 2005 at 01:20:53PM +1300, Christopher Sawtell wrote:
>  
>
>>  I wonder if all the different numbers are being caused by folks
>>having different settings for their CPU speed settings
>>i.e. throttling levels etc.?
>>    
>>
>
>Interesting.  I hadn't considered that possibility, so I tried it.
>
># cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq 
>  1197000
># hdparm -t /dev/hda
>  /dev/hda:
>  Timing buffered disk reads:   54 MB in  3.01 seconds =  17.93 MB/sec
># hdparm -t /dev/hda
>  /dev/hda:
>  Timing buffered disk reads:   60 MB in  3.05 seconds =  19.67 MB/sec
>
># cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 
>  1197000 798000 
>
># echo 798000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed 
># cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq 
>  798000
>
># hdparm -t /dev/hda
>  /dev/hda:
>  Timing buffered disk reads:   60 MB in  3.07 seconds =  19.54 MB/sec
># hdparm -t /dev/hda
>  /dev/hda:
>  Timing buffered disk reads:   60 MB in  3.07 seconds =  19.54 MB/sec
>
>So an interesting hypothesis, but on my system at least it doesn't
>seem to have an effect.  
>
>--nate
>
>BTW, I'm normally running powernowd, and finding it to be a very
>effective solution for selecting CPU speed on demand.  Obviously, I
>turned it off before I ran these tests.  I did, right? :)
>  
>
I have a T42 suposedly 5200RPM

alejandro:~# hdparm -t /dev/hda

/dev/hda:
 Timing buffered disk reads:  102 MB in  3.01 seconds =  33.88 MB/sec