Re: USB Port speeds
Hi,
> The format
> option of -spare=none did help to at least double the performance as you
> thought. I was able add the parameter to the command in K3B settings as
> well.
At least with previously used BD-RE media it will not help to
have this option with growisofs. It is intended to prevent
auto-formatting of blank BD-R media. There it is beneficial indeed.
BD-RE must be stripped of their Spare Area by dvd+rw-format.
> the search
> button in K3B would not offer any other choices than what was provided.
They ignore my programs since years. (Shrug)
> So the performance doubled as you expected but still nowhere near what the
> DVD performance was able to get. (4500 KB/s vs. 14000 KB/s)
2x BD speed should be about 9000 KB/s.
4500 still looks like checkreading.
What speed reports do you get from
dd if=/dev/zero bs=1M count=1000 | \
xorriso -as cdrecord -v dev=/dev/sr0 -
and from
dd if=/dev/zero bs=1M count=1000 | \
xorriso -as cdrecord -v dev=/dev/sr0 stream_recording=on -
> Would I still have the same problem if directly attached to a SATA port? It
> sounds like I would.
If you can test it then we would know whether the USB driver
is involved.
With my own USB attached drives i have problems when speed
gets to 12x DVD which is about 16 MB/s. On a slightly more
modern machine, the same USB boxes run up to 20x DVD speed.
On my olde machine, the block device driver can read with
about 20 MB/s whereas my userspace MMC driver gets only
16 MB/s. There seem to be timing and priority problems.
A SATA attached DVD burner at the old machine does 20x
with my userspace driver.
But that all happens far above 10 MB/s.
> At this point I am not sure as to what is the best direction, look for
> another drive or different media. Any thoughts from your past performance /
> experiences?
> Would drive firmware update help this issue (if available)?
I don't think it is a matter of the BD-RE media if they are
really formatted to 0 Spare area. Bad media would cause write
errors or read errors but should not be slow if Defect Management
is sucessfully disabled.
To verify that state, run
xorriso -outdev /dev/sr0 -list_formats
It should report before a list of format proposals:
Format status: formatted, with 23866.0 MiB
BD Spare Area: 0 blocks consumed, 0 blocks available
> I also have 6x BD-R media but since they are not erasable I prefer not to
> just waste them on silly tests to determine what performance I can get.
There is the "CLOSE SESSION" bug of growisofs with BD-R.
You may want to try my fix proposal for growisofs_mmc.cpp as of
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=713016
before or after you got hit by that bug.
When it seems necessary to waste BD-R, then you may leave them
appendable (by xorriso -as cdrecord option -multi) and make more
than one experiment with the same medium.
About 22 sessions of 1 GB should fit. Probably one could reduce
session size to a few hundred MB and still get meaningful
measurements.
But for now, 2x BD-RE is a good goal.
Have a nice day :)
Thomas
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