Noons wrote:
> VC wrote:
>
>>>I had thought rotational waits were dominant over head-seek waits
>>>these days.
>>>
>>
>>No, even "these days" seek time is still the major factor:
>>
>>200GB Seagate :
>>Rotational Speed 7200 revolutions per minute
>>Average Rotational Delay 4.16 millisecond
>>Average Seek Time 8.5 millisecond
>
>
> Yup, that is very much what I've seen in disk specs
> as well. More so with speeds of 10krpm. In fact, I read
> somewhere that disk optimizers in SANs and intelligent
> controllers don't take into account rotational waits
> anymore, seek speeds being a lot more relevant.
Of course with the new SANS and similar arrays what counts
is writing to the cache more than writing to the physical disks
in most systems.
--
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)
Received on Sun Jun 12 2005 - 20:25:20 CDT
