Re: Disk Performance

[Ben Greear <greearb@candelatech.com>]

Stefan Smietanowski wrote:

> Hi.
> 
>> Why does my 40 Megabyte per second IDE drive, transfer files at best 
>> at 1-2
>> Megabytes per second? Can anyone prove that this must be the case? 
>> What is
>> the most efficient way to convince anyone who reads this that it can't be
>> proven because a counter example exists?
>>
>> I wish to be personally CC'ed the answers/comments posted to the list in
>> response to this posting.
>>
>> This is my first attempt at being part of the process. Please give me 
>> some
>> time to adjust.
> 
> 
> 40Megabyte per second you say. Well, if it benchmarks at 1-2 Megabytes 
> per second it sounds like a 2 Megabytes per second drive to me, not a 40 
> Megabytes per second drive.
> 
> But, to try to speed it up, make sure you're running with DMA mode enabled.
> 
> hdparm -d1 /dev/hdx where x = number of drive (a=primary master, 
> b=primary slave, c=secondary master, etc).
> 
> But, apart from that, if it indeed is a real problem, what's the name of 
> the motherboard, chipset, hard drive, what linux kernel revision are you 
> running and do you use any special patches or tricks with it?
> 


I once had a problem where the cable was attached in the middle, and the end was
not attached to anything (the cable supported two drives).  After changing to
the end connector, it went from 2MB to 30+MB....

Ben


> // Stefan
> 
> 
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-- 
Ben Greear <greearb@candelatech.com>       <Ben_Greear AT excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear