# assumind idebus=33mhz

## tba

i get that message during boot.

my idebus is 100mhz so i override with idebus=100 but i dont see any performance increase.  the only time my performance is bad is when i am searching for something (using kfind  :Smile:  )  then it gets really choppy.

i have an athlon xp and a 40g WDC hard drive (last years model)

here are the results of hdparm /dev/hda

```

multcount    = 16 (on)

 IO_support   =  1 (32-bit)

 unmaskirq    =  1 (on)

 using_dma    =  1 (on)

 keepsettings =  0 (off)

 readonly     =  0 (off)

 readahead    =  8 (on)

 geometry     = 4865/255/63, sectors = 78165360, start = 0

```

and here is the throughput test...

```

Timing buffer-cache reads:   128 MB in  0.65 seconds =196.02 MB/sec

 Timing buffered disk reads:  64 MB in  1.88 seconds = 34.02 MB/sec

```

"does that look right for a fairly new system" is my only question.

thanks in advance

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## delta407

200 MB/s across the IDE bus is quite good, as is 34 MB/s off the disk. You're fine.  :Wink: 

For searching, put updatedb in your crontab somewhere; I think kfind can use the locate database if it's present, but I'm not sure.

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## Naan Yaar

Looks about right.  My <1 year system tops out at about 32MB/sec from "hdparm -t".

 *tba wrote:*   

> i get that message during boot.
> 
> my idebus is 100mhz so i override with idebus=100 but i dont see any performance increase.  the only time my performance is bad is when i am searching for something (using kfind  )  then it gets really choppy.
> 
> i have an athlon xp and a 40g WDC hard drive (last years model)
> ...

 

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## tba

thanks again guys

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## tba

i added updatedb to crontab but i have to say it looks out of place.   ill know how out of place nectime i reboot  :Smile: .  should i run it weekly?  there is nothing in the /etc/cron.weekly/.list files.  i notice if kfinds is running itllll take up 80%+ of my memory....  that cant be normal.

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## delta407

Hmmm... doesn't seem to use the locate database, nevermind. Guess you're screwed with KFind.  :Very Happy: 

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## Disquiet

I think you guys have got the wrong idea about what idebus does...Here's a snippet from the kernel docs:

"idebus=xx"            : inform IDE driver of VESA/PCI bus speed in MHz,

                                where "xx" is between 20 and 66 inclusive,

                                used when tuning chipset PIO modes.

                                For PCI bus, 25 is correct for a P75 system,

                                30 is correct for P90,P120,P180 systems,

                                and 33 is used for P100,P133,P166 systems.

                                If in doubt, use idebus=33 for PCI.

                                As for VLB, it is safest to not specify it.

                                Bigger values are safer than smaller ones.

So it would seem 33 is a good value, and 100 is a value outside the range...so probably doesn't do anything.

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## tba

Disquite,

idebus=66 doesnt help hdparm -tT either but i guess ill put it in rc.start anyway...

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## Sesquipedalian

33 is the correct value.   Your IDE controller hangs off of the PCI bus which runs at 33 MHz.  Unless you have a board with 66MHz/64-bit PCI bus and an IDE controller that uses it (I don't think there are any, that would just be silly),  it is set properly.

- Sesq

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## Malakin

You're mixing up the ata speed with the ide bus frequency. As was already said your ide bus does indeed run at 33mhz.

Type this "hdparm -i /dev/hda" and it will tell you what udma mode you're using.

udma2 = ata33 = "hdparm -X66 /dev/hda"

udma4 = ata66 = "hdparm -X68 /dev/hda"

udma5 = ata100 = "hdparm -X69 /dev/hda"

udma6 = ata133 = "hdparm -X70 /dev/hda"

An 80 pin ide cable is required for modes past ata33.

The kernel should automatically choose the highest setting available for your setup.

Anything past ata66 won't make any differnece unless you have an unusual setup, raid striping for example.

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