On 23/07/2018 07:55, Jan Panteltje wrote:
> On a sunny day (Sun, 22 Jul 2018 17:43:33 -0400) it happened Dennis Lee
Bieber
>  wrote in
:
>
>>         I wouldn't consider read timings to be of significance.
>
> Do not move the goal posts.

I'm pretty sure it was you who moved them from talking about writes to
reads!

With flash the reading is very different to writing, and the performance
of one doesn't tell you anything about the other.

[Snip pretty much the same read results as before]

>>         Class-10 cards are rated for streaming a single (video) file to a
>> freshly formatted card, and may be totally trashed by small random (photo
>> creation/deletion) files. Oh, and that is FAT file system -- just the open
>> file and the open FAT area, for two allocation units at a time.
>
> Straw man
> Note that writing an image back to a card is totally unrelated to what sort
of filesystem is in use.

No, you misunderstand, it's not the filing system in the image that
matters, but what filing system the controller in the SD card is
optimised for. On some cards if you do not write to a card in the way it
would be written to by a FAT32 filing system (use a different filing
system or even raw writes), you get very poor performance.

> But next time I need to write back a raspi backup image (hope it never
happens) I will show the write timings with - and without bs=1M.

We look forward to it.

---druck

--- SoupGate-Win32 v1.05