On Mon, 17 Oct 2016 21:18:18 +0100, pamela wrote:

On 11:42 17 Oct 2016, T i m wrote:

On Mon, 17 Oct 2016 11:31:48 +0100, John Rumm
wrote:

On 17/10/2016 10:45, The Natural Philosopher wrote:
On 17/10/16 09:37, John Rumm wrote:
In reality it could be anywhere on any boundary the
SSD firmware and processor puts it.

Not quite - there is not a one to one mapping of OS
allocation units to flash pages. For optimum performance you
need to ensure that whichever allocation unit you update, the
SSD can do that update by operating on one (and only one)
page of flash. With the wrong alignment, you can end up with
the SSD needing to do two page updates for each OS allocation
unit update.


However all that may be true, but its not under user level
control via partioning, and its handled internally by the SSD.

There is no obvious way a SSD could make a sensible choice to
internally remap alignment if it turns out you have managed to
install an OS partition with a start LBA offset from the ideal.
Especially as one physical drive can host more than one
partition, and if you really tried, you could end up with
several partitions each with different alignments.

It makes far more sense to ensure the partitions are aligned so
that the OS allocation unit is on a 4K boundary (which is the
default action on a modern OS anyway)

So and irrespective of any performance impact ITRW, if some
software (Gparted) can see and display that these alignments
aren't made *and* can set them, is Gparted actually then
*actually / physically* resetting said alignments or just
indicating it is?

What would be a good (valid) way of checking for such things
(increased performance hopefully) pre and post adjustment?

It all sounds like re-numbering sector to reduce latency with
Optune all those years ago. ;-)

Cheers, T i m

You can still buy Spin Rite which used to do that sector
interleaving.

Hmmm, I though I remembered using Optune for that but now you have me
thinking it could have been SpinRite. I'm pretty sure I used both at
the time though, along with NDD and NC.

http://www.danielsays.com/ss-gallery-dos-optune-12.htm

This looks more familiar though ...

https://en.wikipedia.org/wiki/SpinRi...inrite-2.0.png


It now has other bells and whistles, some of
disputed benefit, for a mere $89!

Bargain. ;-)

Cheers, T i m