Change UDMA level in running system (was Re: disk problems or false alarm??)

[Jeff Vian]

bit wrote:

>Am Samstag 01 Mai 2004 01:18 schrieb Alexander Dalloz:
>  
>
>>Am Sa, den 01.05.2004 schrieb Guolin Cheng um 00:51:
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>>
>>>Hi, William,
>>>
>>> Thanks.
>>>
>>> Then how to increase PCI IDE disk speed through adjusting PCI bus
>>>speed? What I've said is: even I tried to improve PCI bus speed by
>>>specifying "idebus=66", the sustainable PCI IDE disk data transfer speed
>>>is still about 33MB/s, while the hard disks themselves may be capable of
>>>providing higher speed. Thanks.
>>>
>>>I definitely know apple and orange, both fruits are my favorite. :)
>>>
>>>Guolin Cheng
>>>      
>>>
>>Do not play with idebus=XX setting, it's pointless. Instead run "hdparm
>>-i /dev/hdX" where X is the drive letter. It will print with which mode
>>and at which speed rate the drive actually works:
>>
>> PIO modes:  pio0 pio1 pio2 pio3 pio4
>> DMA modes:  mdma0 mdma1 mdma2
>> UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
>>
>>This example shows the drive is capable or PIO mode, DMA modes and UDMA
>>modes. And it shows that the current mode and speed is UDMA5.
>>
>>    
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>
>Using "hdparm -i /dev/hdX", I found out, that both of my hard drives run in 
>udma2, while they are capable of udma5.
>
> PIO modes:  pio0 pio1 pio2 pio3 pio4 
> DMA modes:  mdma0 mdma1 mdma2 
> UDMA modes: udma0 udma1 *udma2 udma3 udma4 udma5 
> AdvancedPM=yes: disabled (255) WriteCache=enabled
> Drive conforms to: ATA/ATAPI-5 T13 1321D revision 1: 
>
>I didn't investigat this any further, apart from reading the hdparm man pages, 
>but is it advisable to change from udma2 to udma5 in a completely installed 
>and configured OS generally (or FC1 in special) ?
>
>Sorry for hijacking the thread, but I felt it was kinda "apropriate". :-)
>
>Thanks for any help.
>
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>
What are you using for a drive cable?   UDMA/cable select, or the old 40 
pin cable?
the 80 trace cable must be used for the higher speeds.

What is the controller you are using?  I assume ultra, but need to be sure.

What is the BIOS setting?.  If not set to ultra it will not work any faster.

>>Alexander
>>    
>>
>
>Have phun,
>bit
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