This has been our first endurance test of an SSD. At the
beginning of this diary we've been trying estimate how long it will take until
the drive is going to die. It turns out that calculating with 5'000 P/E-cycles
was a reasonable thing to, since in the end the drive achieved 5'129 P/E-cycles.
We were guessing the drive would withstand our torture testing of continuous
writing for 125 days and that turned out to be close to the actual value too,
whereas the final result was 142 days.
If we start to do the maths, based on the values we gathered we're going to see
some rather surprising endurance values. OCZ specifies this drive to be capable
of enduring 20 Gigabyte written per day over a time period of five years. This
is what the manufacturer of this drive guarantees. As you can see from the table
below, based on our results, when writing 20 Gigabyte per day, you could use
this drive for 121 years. This is over 24 times more than actually advertised
and it gives you a feeling on how conservative manufacturers are when it comes
to endurance ratings of their SSDs. Even if you were writing 50 Gigabyte per day
the drive would still last 48 years and at 100 Gigabyte per day this Vector 256
GB would run for 24 years.
Lately another endurance rating used by manufacturers started to appear. Now the
vendors are talking about drive writes per day. Some enterprise grade SSDs for
example are capable of delivering ten drive writes per day over five years. Pair
this up with a drive capacity of 1 Terabyte and you will get some seriously high
numbers. Calculating drive writes per day (DPWD) for the Vector 256 GB we've
been testing here, when factoring in a period of five years, we end up with a
value of 1.89. In the end this means you could be writing the capacity of the
drive over 1.8 times per day for five years.
Since the Vector 256 GB is a consumer drive and consumers will be the ones
buying and using such a drive, a suitable use case should be applied. In case of
an average user it's highly likely that no more than 20 Gigabyte will be written
on the drive per day, which is over 24 times less then what the Vector 256 GB
could actually do.
|Data written per day