Yes wrote:
I'm in a quandary, I'm interested in replacing some of the HDs I have
(they're around 5 years old now) or at least having a new one on hand
as a spare for when needed but want to be figure out if it makes sense
to shift to portable HDDs from internally mounted HDDs. My current
uses are email, web surfing, vintage (ca. 1990s and early 2000s) RPG
games, and periodic file backup. The two portable HDDs I have are used
for medium term backup of data files. I keep them unplugged from my
system when I'm not backing up files.
Ad prices of 2TB portable HDDs seem quite a bit lower compared to
equivalently sized internally mounted HDDs. I've seen WD 2TB portable
drives (USB 3) advertised for anywhere from $60-70 and the same vendor
advertising WD 2TB Black HDDs (SATA 3) around $110. Quite a bit of a
price difference.
Excluding the convenience of a portable drive, are there quality
performance or durability reasons to prefer one type instead of the
other.
From what I've read, USB 3.0 is relatively close in throughput speed
with that of SATA 3. Is there enough experience now with portable HDDs
compared to internal HDDs to indicate how well and how long the two
types of drives last before breakdown?
Thanks,
John
You read the customer reviews for a HDD product, to determine
if there is an issue with them.
For example, a disk I bought, a reviewer said "there is a funny
noise when it shuts down". I bought one anyway, knowing this
was a *design* issue and not a product quality issue. His
wasn't going to be the only one. And yes, mine makes that
accursed noise. The rule of thumb is "the more noise a
drive makes, the sooner it breaks down". Because noise equals
friction, friction makes dirt, dirt pollutes the insides
of the "Class 10 clean" HDA enclosure. It must remain
super-clean in there, for a long life. The noise sounds
to me like a dry FDB motor bearing, during shutdown.
A lubrication problem of some sort. (No, you can't
do an oil change :-) )
*******
Drives are segregated a bit, according to performance.
The seek time can be reduced a tiny bit, on the more
aggressive designs. The Black drive is supposed to be
the most aggressive drive. But it's similar to some
of WDCs Enterprise offerings, which also have fast seek.
The fast seek drives, when securely bolted inside your
tower, you'll hear "rumbling" from the violent seeking.
Maybe the seek time is 12 milliseconds as measured.
Lots of home users complain about the noise from the
Black, but it doesn't bother me too much.
Drives where the seek is turned down, the acceleration
curve for the head assembly isn't quite as violent and
abrupt. The noise level of the drive drops. But the
seek time might now be 16 milliseconds. That means
the possibility of fewer head movements per second,
important for random file transfers.
You'll find the performance numbers are all over the
place. When I bench these things, I'm finding "aggressive"
branded drives, with "green" (wimpy) performance characteristics.
All we can say in 2017, is we're getting the shaft,
when the manufacturer cannot even keep its branding
straight. You might be getting a "$70 drive" when
you buy the "$110 product".
The 2.5" drive, the seek time is likely to be a lot slower.
It would make a lousy OS boot drive. It makes a "just fine"
backup drive, as backups can be mostly sequential, and
the heads don't move violently.
As long as you understand what the final purpose
of the drive will be, you can try to make an
intelligent choice. The WDC Black might be intended
for a boot drive. But with the practice of shafting
consumers, you don't really know what the seek time
will be, until it arrives.
"Slow" drives for backup, isn't the end of the world.
Modern commodity 3.5" drives will do 200MB/sec on the
outer diameter, 100MB/sec on the inner diameter. This
is a lot faster than the 60MB/sec rubbish in my
older disk collection.
USB3 enclosures, even the junky ones, do 200MB/sec. The
enclosure is then not a limit for the HDD selected for
the enclosure.
The absolutely fastest HDD made today, is 15K, it has
a really low seek time, and the sequential transfer
is 300MB/sec. That gives you some idea what the
read channel bandwidth capabilities are, and how
far (some day) our commodity drives could go, given
the right set of conditions. You cannot live in the
same house with those drives - the noise level is
suited only to server rooms. The whine and chirping
would drive you nuts.
USB3 includes UASP. With UASP (SCSI protocol) driver
installed, with an "unlimited" USB3 controller in
the Southbridge, the fastest sequential over conventional
USB3 is ~450MB/sec. This is SSD speed. A SATA III SSD
placed in the enclosure, will allow that speed to be
realized. The best I can do with mine right now,
is around 300MB/sec. I don't have the right plumbing
for heroic benchmarking.
When the motherboard has an "add-on" USB3 controller, the
PCI Express interconnect is a bottleneck. And it happens
to clip things around 200MB/sec. So now you can have two
bottlenecks - the enclosure controller at 200MB/sec and
the host controller at 200MB/sec. In other words, with
the worst rubbish the electronics industry has to offer,
the HDD speed is fully used :-) It takes a good deal
of effort to select the right components to get higher
than that.
There is a newer version of USB that runs at 10Gbit/sec
instead of 5Gbit/sec. The only purpose-built storage
for it so far, benches at around 700MB/sec. It's an
SSD drive with a USB3 Type C connector. And it's
relatively expensive. But you don't get a lot of capacity,
and it's relegated to winning bar bets.
The advantage of 3.5" drives today, is you can get
some pretty large ones. You can get 10TB or 12TB drives.
When the drives get big enough (2TB), you need to use GPT
partitioning, which means the drive might not be
visible on an ancient OS. On my WinXP for example,
if I want to run a backup to a GPT drive, I can boot
my Win8.1 OS, and do the backup of WinXP from there.
As Win 8.1 supports GPT, whereas my WinXP does not.
There might have been some add-on for WinXP, to make
it support GPT, but I haven't tracked that down or
tested it, whatever it is.
The SMART statistics from a hard drive, can give
some level of "health" information, so for the
older drives, you could check whether the
"reallocation" field in SMART has gone non-zero.
A just-as-valid check, is to bench the drive and
see whether the curve has any serious divots in it.
https://s33.postimg.org/ee9ti1m67/startstop.gif
This is a brand new drive, being benchmarked.
http://www.hdtune.com/images/screenshot.png
Whereas this one probably has a lot of reallocations
to slow it down. This one would go in my "scratch
drive" pile. I certainly couldn't run this as
a boot drive. Sluggish. And annoying.
http://forum.notebookreview.com/atta...une-jpg.49651/
Paul