Re: SSD Drives

On 4/4/2014 5:29 PM, Lists wrote:
> So, spend the money and get the enterprise class SSDs. They have come
> down considerably in price over the last year or so. Although on paper
> the Intel Enterprise SSDs tend to trail the performance numbers of the
> leading consumer drives, they have wear characteristics that mean you
> can trust them as much as you can any other drive for years, and they
> still leave spinning rust far, far behind.

Another issue to bear in mind is that SSD performance may not be
consistent over time. This is because the software on the drive that
manages where data lives in the NAND chips has to perform operations
similar to garbage collection. Drive performance may slowly decrease
over the lifetime of the drive, or worse : Consumer drives may be
designed such that this GC-like activity is expected to take place "when
the drive is idle", which it may well be for much of the time, in a
laptop. However, in a server subject to a constant load, there may never
be "idle time". As a result the drive may all of a sudden decide to stop
processing host I/O operations while it reshuffles its blocks.
Enterprise drives are designed to address this problem and are specified
for longevity under a constant high workload. Performance is similarly
specified over worst-case lifetime conditions (which could explain why
consumer drives appear to be faster, at least initially).