Re: Could RAM possibly be just 3-4 times faster than bare hdd ...

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

all your dd runs are allowed to make heavy use of RAM buffering.
If you are interested in the speed of the storage device, add option
  oflag=dsync
to the dd run.

I use dd options
  bs=1M status=progress oflag=dsync
in order to get realistic pacifier messages when copying ISOs to USB stick.
The overall time until a 35 MB/s stick stops blinking is not longer than
without those options. Just progress is smooth and dd does not end before
the stick is done with blinking.

Maybe bs=4K is a bit small for oflag=dsync and unrealistic in comparison
to Linux kernel behavior about disk i/o.


Have a nice day :)

Thomas