Re: Unbelievable slow speeds when burning DVDs

[Vasileios Gkanis <gkanis@cems.umn.edu>]

> > cdrecord has a special option for this case: -immed (see man page)
> I burned some data (4.3GB) on two discs. The first disc was burned with the 
> "-immed" option and the second disc was not. Unfortunately, the first disc 
> was lost, some of the data can not be read. Both discs were burned at an 
> average speed of ~2x and the maximum speed was ~4x. But, when I used the 
> "-immed" option I burned only 100MB at ~4x, and then the speed dropped to 
> ~2x. When I did not use this option I burned about 500MB at ~4x, and then 
> again the speed dropped to ~2x. Interestingly, the speed increased from ~2x 
> to ~4x when about 500MB were already written on the disc. But before it 
> increased, the hard disk stopped transfering any data, the speed dropped to 
> ~0.1x and stayed there for a couple of seconds, and then it increased to 4x.
>
> Do all these make sense? Do you think this is normal?
> Without any information nobody can help you
>
>
> http://cdrecord.berlios.de/old/private/problems.html
>
> Jörg
Yes, you are right, I am sorry about that. Let me start with the very basic:
OS: Gentoo
Kernel: 2.6.12_rc6 love-srouces
Cdrecrotd-Prodvd: 2.01.01
Mkisofs: 2.1
The DVD disc was a Verbatim 16x DVD-R, and the driver is QSI DVD+/-RW SDW-082 
(Firmware LX44) with maximum speed 8x.
The command that I issued (as root) was
mkisofs -V "Data" -R /home/vasilis/data/ | /root/cdrecord-wrapper.sh -v -sao 
tsize=2276518s -dev=ATA:0,1,0 driveropts=burnfree speed=8 -           

The DVD disc was burned without any error, but the burning speed was increased 
to ~4x, for a couple of minutes, and then it decreased to ~2x. The hard disk 
was always transfering data, but when the burning speed changed to 4x and 
then back to 2x, for a couple of seconds the hard disk stopped transfering 
data.

The system is a Centrino at 2Ghz with 512MB RAM, dma is enabled on both hard 
disc and DVD drive. hdparm -tT /dev/hda shows that the maximum transfer rate 
from/to the hard disc is ~30MB/s.
The system has and IDE controller
0000:00:1f.1 IDE interface: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 
Family) IDE Controller (rev 04)
which is supported in the kernel.

I do not know if these informations are helpfull, but this is all I got. If 
you want me to send you the output of cdrecord-prodvd -V, I will gladly do 
it.

Thank you,
Vasilis