Toshiba AL13SXB600N 15,000rpm 600GB SAS HDD Review

Power Consumption and Data Reliability

Power Consumption

I believe most people know that data centres are already one
of the major consumers of electricity in the industrialised world; indeed it is
estimated that currently 2% of all electricity consumption goes into IT
applications.  According to the European Union the energy consumption of data
centres was 46 Terawatt hours in 2006 and is set to rise to 93 TW hrs by 2020. This
is equivalent to one hundred million 100W light bulbs burning 24 hours a day,
365 days a year.

Typically 40% of the power consumed by data centres is for
the IT load and 35% is for cooling the system.  Generally speaking, if a drive
consumes more power it will produce more heat – so power consumption is indeed
a double edged sword.  It is no surprise then that a significant proportion of
a data centre’s power consumption goes on servers.  I understand cloud based
applications, such as Facebook, are the primary cause of the growth in servers
and the demand for storage space.

If you are a Facebook user, like me and the Reynolds sibs, and
you reside in Europe – this is most probably where your data is click here.  Some
interesting Facebook statistics – Facebook has more than 1 Billion monthly
active users, it generates 1 Trillion page views per month and more than 219
Billion photos have been uploaded since launch – amazing!  Here is an
interesting video showing the remarkable scale of Facebook’s largest North American
data centre click

My thanks to Anna of Intel for pointing me to the following
Info-graphs –

Toshiba AL13SXB600N 15,000rpm 600GB SAS HDD Review


Toshiba AL13SXB600N 15,000rpm 600GB SAS HDD Review


Power Testing – Sneak Preview

Here is another quick preview of one of the examples of the
power testing that we will soon be adding to our standard tests for enterprise

Power testing will be performed by a Quarch Technology
12v/5v Programmable Power Module (QTL 1455).  OakGate has added integration
with Quarch Technology products so that I will, for example, be able to graph
power consumption alongside drive performance for long durations.  We will soon
publish a press release to mark the formal launch of our partnership with
Quarch and this will be accompanied by an article which will detail the
standard power tests that will appear in our reviews (it will also establish an
initial set of results for several leading drives).

In this preview we are utilising a direct connection to the
Quarch PPM (rather than via our Oakgate unit) to measure the power
characteristics of the THNSNJ960PCSZ whilst it performs a heavy workload of 4K
random writes.

Here is a visual presentation of the result –

Toshiba AL13SXB600N 15,000rpm 600GB SAS HDD Review

You can see that the AL13SXB600N is drawing power from both
the 5v and 12v rail.

Here is an extract from the raw data that was captured
during the observation period –


Toshiba AL13SXB600N 15,000rpm 600GB SAS HDD Review

You can see that the PPM is taking a measurement every 4
microseconds (every 4 millionths of a second! i.e. at 250KHz) and is recording
results with a truly phenomenal level of precision!


Here is a display of the key statistics from the observation
period –

Toshiba AL13SXB600N 15,000rpm 600GB SAS HDD Review

You can see that the average power consumption was 2662mW
(2.662W) on the 5v rail and 5346W (5.346W) on the 12v rail giving a total of
8.008W and this compares favourably to Toshiba’s specification of 9W when

For more information regarding Quarch Technology, please see
their web site by clicking here.

Data Reliability

The ‘Unrecoverable Bit Error
Rate’ (UBER),as defined by JEDEC, the global leader in developing open
standards for the microelectronic industry, is a metric for data corruption
rate equal to the number of data errors per bit read after applying any
specified error correction method. UBER = number of data errors / number of
bits read.  JDEC specifies that the maximum error rate allowable for an
Enterprise level SSS solution is one error in every 10^16 bits read.

Toshiba specifies an UBER of 10 errors in 10^17
bits read
for the AL13SXB600N (or 1 in 10^16).

Toshiba AL13SXB600N 15,000rpm 600GB SAS HDD Review


Toshiba specifies a Mean Time to Failure (‘MTTF’) for the AL13SXB600N
of 2,000,000 hours (228 years!)

The AL13SXB600N provides all of the failover options enabled
by SAS 2.0.  Please see here
for an overview of the advantages enabled by SAS.


Now let’s head to the next page, to look at the
Conclusions of this review…..