Andy said:
I have a Toshiba 500 Gb external drive.
I am trying to determine if it is a platter drive.
When I hold my ear against it, I can hear humming.
Would a solid state drive do that ?
Using a benchmark software, do a seek time test.
On HDTune, they measure seek time after the main
benchmark run is done. These would be the numbers
a home user might see, on commodity equipment.
Spinning drive - 12 milliseconds (pretty well any interconnect)
SSD over USB2 - 1 millisecond
SSD over USB3 - (a little lower)
SSD over SATA - 0.1 millisecond (lower limit 0.020 milliseconds)
There is sufficient difference between "spinning drive"
and all the rest, to tell the difference. Even if you
retort with "your numbers are wrong for 15K drives",
I would reply you can still tell the difference between
the hard drive full stroke seek and the SSD. It should
be an observable difference. The spinning drive cannot
get close to the 1 millisecond number, if the head is
made to move any appreciable difference. You'd have to
cheat and do "head switch" benchmarks to get even close.
A head switch might get close to a millisecond.
*******
The table of SMART statistics coming from an SSD,
is also different than the table from a spinning drive.
But not all interconnect methods guarantee access to
SMART.
So the seek time test will have to do. Because
it might be harder for a user to figure out how
to access SMART.
*******
SSD power consumption covers a wide range. SSDs with
a Sandforce controller, compress the data, and the peak
power when doing so, will be higher than on competing
SSDs. And we can't even be sure the various SSD
makers are comparing power numbers for matching
test conditions (comparing a "sleep" number to
an average or a peak write number). All I can suggest
is, the Sandforce based one might be "lukewarm",
while the others are "ice cold". As an approximate metric.
SSD drives are working, even when you're not reading
or writing them. They can be busy working on the flash
chips. After a "4K random read/write test" has been
carried out (see a review site), the poor SSD may end
up doing maintenance on the drive, all night long. In order
for the drive performance level to be "normal" the next
day. If your SSD drive is not abused, it will have little
maintenance to do.
When a hard drive is idle, it doesn't work nearly as hard.
The only maintenance it might run, is a SMART test once in
a while (to detect imminent failure).
Some server drives, do a "burst read" every 71 seconds, which
apparently makes an annoying audible sound. The commodity
disk drives in your desktop computer, don't do that particular
test. It's not clear to me, what benefit such a test provides,
other than to keep IT staff awake
Paul
