On Mon, 21 May 2018 00:04:56 +0100, Paul wrote:

Jimmy Wilkinson Knife wrote:

I have noticed my SSD maxed out now and then when Windows decides I'm
not using the computer. No idea what it's up to, since I assume SSDs
don't need defragmenting.

Do SSDs slow down when they're nearly full, or when they're old? I'm
sure mine isn't as fast as it used to be.

The ones I've got have maintained their performance
level fairly well.

I've never benchmarked mine, so I'm just going subjectively. I never used to be waiting for the computer to do something, and realise it was the SSD causing the bottleneck.

The very first one I bought (Corsair Neutron?) was a dud,
and performance in the first day, varied between 120MB/sec
and pretty close to the available SATAIII rate. I took it
back for a refund, after only 50GB of writes. I hadn't intended
to "benchmark it", but the damn thing was slow enough to notice
and I was pretty well forced to collect some graphs and
take it back to the store. It was well off the rates
printed on the tin.

I used to get OCZ SSDs (not sure why, maybe price?) - but I had literally one in 5 of them fail completely. I now use Crucial, which 100% work and never go wrong (except a couple that needed firmware upgrade as they "disappeared". Looking at current reviews, OCZ are also the slowest, not sure why they're sold at all.

*******

If the issue was internal fragmentation, you could back up,
Secure Erase, and restore.

What do you mean "internal fragmentation"?

And surely fragmentation only matters on a mechanical drive, as the heads have to read data from several different places. This won't slow down an SSD?

If you happen to have a lot of persistent VSS shadows
running on the system, there can be "slow copy on write",
and the OS Optimize function will actually defragment an SSD
if such a condition is noted. I still haven't located a tech
article to decode how "slow COW" happens or why it happens.
There is some deal, when you defragment a drive, the defragmenter
is supposed to limit cluster movements to certain sizes, to prevent
interaction with a Shadow which is already in place. It's possible
shadow copies work at the cluster level.

I thought SSDs should never be defragged, and the data storage position was handled internally to the drive. I read something about running a defrag program on an SSD just wore it out.

An example of a reason to use a Shadow, might be File History,
or it might be the usage of Incremental or Differential backups.
There are some commands you can use, to list the current
shadows in place. WinXP has VSS, but no persistent shadows
are available, and a reboot should close them all. Later
OSes allow keeping a shadow running between sessions
(for tracking file system state). The maximum number
of shadows is something like 64.

vssadmin list shadows

[vssadmin]
https://technet.microsoft.com/en-us/.../dd348398.aspx

I'm not familiar with shadows. Is that what allows me to use something like EaseUS Backup to clone a drive while windows is still running?

--
Beelzebug (n.): Satan in the form of a mosquito that gets into your bedroom at three in the morning and cannot be cast out.