[resolved, naively] Re: geom vs ich through ar device -

[Howard Goldstein]

Jeremy Chadwick wrote:
> On Wed, Jul 25, 2007 at 07:02:58PM -0600, Scott Long wrote:
>> You should be able to sustain at least 70MB/s on a single modern drive
>> with SATA-1 or SATA-2.  If you're not getting that then something in the
>> driver or the application is getting in the way.  Even with the, um,
>> "problems" that SiI controllers are famous for, you should be able to
>> sustain a decent data rate on a single drive.
> 
> Informative thread!  

Agreed.  A snarky attaboy is due to Ultra Products for their part in all
of this starting when they shipped a case+PS with one of the 5 four pin
molex power connectors installed backwards at the factory which  let the
magic smoke out of my original RAID array and having the new drives
arrive from Ultra (after much kicking and screaming on their part, and 6
months later arrrrgh) incited me to ask the question.

(As an aside for consumer grade drive buyers that some of us myself
appear to be including myself, the WDCs do not have any overvoltage
protection and WD claims not to sell controller boards for their
caviars, while Maxtor does have some sort of OVP that sacrifices itself
and shorts the overvoltage rail enough to shut down a 400W power supply
but saves the drive)



> Results:
> 
> [root at icarus ~]# dd if=/dev/zero of=/backup/ddtest bs=1m count=1000
> 1048576000 bytes transferred in 16.249101 secs (64531324 bytes/sec)
> 
> [root at icarus ~]# dd if=/dev/zero of=/home/ddtest bs=1m count=1000
> 1048576000 bytes transferred in 23.940996 secs (43798345 bytes/sec)
> 
> [root at icarus ~]# dd if=/dev/zero of=/storage/ddtest bs=1m count=1000
> 1048576000 bytes transferred in 14.729852 secs (71187137 bytes/sec)

Very interesting! Your /backup and /storage that have WD5000AAKS on
SATAII are roughly comparable to my 7200RPM WD3200AAKS on SATAI.   Do
you think we've saturated the physical storage mechanism in the drives
or are we looking at the drive's controller getting saturated?  Thank
you for posting your results