[ltp] Recommendation for new disk drive

Henrique de Moraes Holschuh linux-thinkpad@linux-thinkpad.org
Fri, 17 Jul 2009 13:41:48 -0300

On Fri, 17 Jul 2009, Igor V. Rafienko wrote:
> on Jul 17, 2009, 11:40, Henrique de Moraes Holschuh wrote:
> >Agreed.  Get a Hitachi if you can, if not, a Seagate is also good.
> >Stay away from data-munchers from Samsung and WD.
> What's wrong with WD? (Just curious).

Well, apart from bad performance, they hate me and break down too soon,
taking my data with it :-)

> To the OP: In case this has not been mentioned, get a drive with its
> own accelerometer (WD has a few models, so does Seagate (their G
> series)). Failing that, get an HDD that supports UNLOAD_IMMEDIATE
> (so you can use hdaps. E.g. Seagate ST9160821A firmware 3.ALE).

Good catch.  BTW, a build-in accelerometer and HDAPS disabled will save
battery power and give you better performance.  The way HDAPS work is *not*
pretty.  They could have done a much better job, but hey, they beat the
rest of the market by two years(!) with it.

> >>1) Doesn't 7200 rpm mean a higher power consumption?
> >
> >Yes, but MUCH better performance.
> Is it? Skimming through, say,
> <http://www.techarp.com/showarticle.aspx?artno=511> shows that for
> certain benchmarks it's far from obvious whether 7200 or 5400 drive
> would do better (I understand why 7200 intuitively should be faster,
> but I honestly do not see the "MUCH better" part. Am I reading the
> test wrong?)

My workload loves 7200RPM (kernel compiles, some multimedia work with crap
messing with the disk in the background).  Maybe yours won't benefit so much
from the reduced latency and improved platter transfer speed, though.

> >If you get a Hitachi, just remember that they ABSOLUTELY REQUIRE the
> >platters to stop at least once every 48H if you want they to last (and this
> >is written in their technical datasheet).  If you let the disk sleep when
> >idle (not just head parking), that can be enough.  If you turn off the
> >laptop often, it is also obviously enough.
> Whoa! I did not realize that. Thank you for the info.

Yeah, people expect laptops to be turned off or put to sleep constantly, and
IBM/Lenovo uses very aggressive power saving modes in the disk, so they sort
of assume the disk will have its power down cycles...

But I have observed that in this list we have some people who leave the
laptop turned on in a table, and the HDs don't come with a big mean sticker
telling you to let it stop the spindle every once in a while (and not less
than once every 48H) to reflow the fluid bearings or else...

  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh