From: John Robinson <john.robinson@anonymous.org.uk>
To: Tim Small <tim@seoss.co.uk>
Cc: Bill Davidsen <davidsen@tmr.com>,
'Linux-RAID' <linux-raid@vger.kernel.org>
Subject: Re: Samsung F1 RAID Class SATA/300 1TB drives
Date: Thu, 04 Nov 2010 11:30:48 +0000 [thread overview]
Message-ID: <4CD29968.9010305@anonymous.org.uk> (raw)
In-Reply-To: <4CD28C2F.8010104@seoss.co.uk>
On 04/11/2010 10:34, Tim Small wrote:
> On 04/11/10 01:54, John Robinson wrote:
>> operating power is 7W, the maximum transition power (whatever that is)
>> is 40W - yes, 40W
>
> I'd guess this is either during spin-up, (or spin speed change if
> enabled), or possibly even the "inrush" current when power is first
> applied to the device (i.e. only for a few milliseconds when the machine
> is turned on), and so probably wouldn't cause much of a problem unless.
Yes, reading the spec more closely indicates that this transition power
is the drive waking up from its lowest power-saving mode, so it's
spinning up the discs, so that's not going to be happening much.
In second place after spin-up events, from the same spec, we have peak
power during random reads of 24W, and 26W for writes, still more than 3
times the average operating power. I take "random reads" to mean lots of
seeks, so as Bill said, heavy seeking could be rather rough on a PSU.
Cheers,
John.
next prev parent reply other threads:[~2010-11-04 11:30 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-28 23:17 Samsung F1 RAID Class SATA/300 1TB drives Mark Knecht
2010-10-28 23:37 ` John Robinson
2010-10-28 23:50 ` Mark Knecht
2010-11-01 21:26 ` David Rees
2010-11-01 21:57 ` Leslie Rhorer
2010-11-03 17:04 ` Bill Davidsen
2010-11-04 1:54 ` John Robinson
2010-11-04 10:34 ` Tim Small
2010-11-04 11:30 ` John Robinson [this message]
2010-11-01 19:50 ` Bill Davidsen
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