[lug] ATAPI->SCSI...was SCSI DVD writers

Gary Hodges Gary.Hodges at noaa.gov
Thu Jul 8 16:10:12 MDT 2004

David Morris wrote:

>On Fri, Jul 02, 2004 at 03:09:02PM -0600, Gary Hodges wrote:
>>I just hooked up an ATAPI->SCSI converter to my Sony DVD+/-RW drive.  
>>Everything seems to be operating as if it was an actual SCSI drive, 
>>though all I've done so far is blank a disk.  It was ~$80 w/shipping.  
>>Here are a few things some of you might like to see.
>I did use one of the converters myself briefly to
>experiement on some CD-RW drives (several years ago now).
>Out of 6 drives I tested, two got confused when trying to
>blank RW media but worked just fine on CD-R media or
>recording on an already blank CD-RW.  The performance
>compared to a true SCSI drive is notably slower (though its
>rarely noticible on a CD/DVD device).  Sustained transfers
>are also slower using the adapter than on the IDE bus for a
>pure read, but faster when a second device is in the loop or
>other processes are running on the computer.
>Let me know if you run into any issues, I'd be interested to
>hear how the DVD-RW performs with the converter.

So far the adapter is working just fine.  Without it when I tried to use 
the DVD writer, my computer ground to a halt.  With it I can use my 
machine for other purposes while writing/reading the DVD drive.  I don't 
have any comparisons with and without the adapter, but I have the 
following results that may be useful.  These tests are writing ~3.6 GB 
data.  Keep in mind that about four minutes is spent running mkisofs 
before the actual write begins.

4x rated +RW media:
space:/data2/TSI # time growisofs -dvd-compat -speed=4 -Z /dev/sr2 -l -r 
-J -v .cd/
real    19m46.155s
user    0m0.664s
sys     0m10.849s

2.4x +R media:
real    23m3.115s
user    0m0.685s
sys     0m11.266s

I'm assuming it was 2.4x media since I specified to write at 4x but I 
got the following message:
/dev/sr2: "Current Write Speed" is 2.4x1385KBps. 

For the 4x media I got:
/dev/sr2: "Current Write Speed" is 4.0x1385KBps

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