Re: cdrecord and "get performance" scsi errors
"Thomas Schmitt" <scdbackup@gmx.net> wrote:
> Hi,
>
> > ...
> > GET [CURRENT] PERFORMANCE:
>
> Looks like a successful command execution.
>
> I would next try wether growisofs is able to burn with
> speeds 2.4 and 4.0.
>
> ----------------------------------------------------------
> Dirty details:
>
> For the SCSI commands involved let's look into
> dvd+rw-tools-7.0/dvd+rw-mediainfo.cpp
> (Search for text "GET [CURRENT] PERFORMANCE)
> As reference i read
> http://www.t10.org/ftp/t10/drafts/mmc5/mmc5r03c.pdf
>
> > Write Performance: 4.0x1385=5540KB/s@[0 -> 2295103]
>
> The CDB would look like
> AC 04 00 00 00 00 00 00 nn nn 00 00
Which does not gve us what we need......
> in comparison to cdrecord's
> AC 00 00 00 00 00 00 00 00 64 03 00
> where "nn nn" is the number of allocated descriptor records
> which "00 64" in case of cdrecord. dvd+rw-mediainfo inquires
> this number first by "00 01" and then allocates the necessary
> memory before doing the real descriptor inquiry.
>
> Reading MMC-5: the difference is the parameter Type
> in byte number 10. dvd+rw-mediainfo here uses Type 0,
> cdrecord uses Type 3.
> The value 04 in byte 1 (parameter Data Type) indicates
> that dvd+rw-mediainfo is interested in write performance.
>
> We learn from the reply that the write performance is up to
> 4x DVD speed. Valid over the sector range from 0 to 4.7 GB.
>
>
> > Speed Descriptor#0: 02/2295103 R@5.4x1385=7449KB/s W@4.0x1385=5540KB/s
> > Speed Descriptor#1: 02/2295103 R@5.4x1385=7449KB/s W@2.4x1385=3324KB/s
>
> This stems from a CDB
> AC ?? 00 00 00 00 00 00 nn nn 03 00
> i.e. with the Type used by the command which has trouble
> within cdrecord.
> MMC-5 says nothing about the Data Type (byte 1 of the CDB)
> with Type 03h. I would expect that ?? is still 04 from the
> previous command.
???
Do you expect a bug in growisofs?
cdrecord uses two different versions:
CDB: AC 00 00 00 00 00 00 00 00 64 03 00
and
CDB: AC 04 00 00 00 00 00 00 00 01 00 00
> We learn from the reply that write speeds 2.4x and 4.0x could
> be set by command B6h SET STREAMING.
> (This is what growisofs or my program cdrskin are supposed
> to do if you let them burn a DVD+RW and order to use those
> speeds. growisofs calculates permissible speeds, cdrskin
> lets the drive calculate.)
it is wrong from my understanding.
What would make sense is to try if there is a bug in the ATAPI <-> USB
adaprot that dauses a DMA error by trying to
reduce the 64 == 100 dec. to a lower number and check again.
Jörg
--
EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
js@cs.tu-berlin.de (uni)
schilling@fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/
URL: http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily
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