Silent errors when reading CDs

[Jean-Sebastien Roy]

Dmitry Morozovsky wrote:

>What if you copy that big file from CD to HD twice (possibly with
>unmounting/remounting in the middle) and check MD5s there?
>  
>
I tried a few times and got no error.

>Testing your memory with memtest86.com's test would also be helpful to
>eliminate RAM issues.
>  
>
Could get memtest86 to run for some reasons, but I tried memtest 
multiple times and got no error.

Yar Tikhiy wrote:

>Once I had an old noname PC (iP200 in an i430VX motherboard), and
>I installed a DVD+RW drive into it.  Data read from a CD or DVD was
>damaged with high probability.  With hw.ata.atapi_dma set to zero,
>the probability of data corruption was lower, but still noticable.
>That's while there were no corruption on burning in DMA or PIO mode.
>  
>
At least I'm not alone !

>Are there CDs in your collection that produce no errors?
>  
>
Yes, but I cannot really tell if it's by chance or they really do not 
produce errors.

>Even a badly scratched CD won't produce damaged data unless read
>in a brain-dead drive.  If your drives work OK with a different ATA
>controller, then it's probably your present ATA controller to blame.
>  
>
The CDs read well in other computers. FWIW, my ATA controler is an Intel 
ICH5 :

atapci0: <Intel ICH5 ATA100 controller> port 
0x24c0-0x24cf,0x280c-0x280f,0x24f0-0x24f7,0x2808-0x280b,0x24e8-0x24ef 
irq 10 at device 31.1 on pci0
ata0: at 0x1f0 irq 14 on atapci0
ata1: at 0x170 irq 15 on atapci0
atapci1: <Intel ICH5 SATA150 controller> port 
0x24d0-0x24df,0x2814-0x2817,0x2800-0x2807,0x2810-0x2813,0x24f8-0x24ff 
irq 10 at device 31.2 on pci0
ata2: at 0x24f8 on atapci1
ata3: at 0x2800 on atapci1
ad0: 38166MB <WDC WD400EB-11CPF0> [77545/16/63] at ata0-master UDMA100
acd0: DVD-R <PLEXTOR DVDR PX-712A> at ata1-master UDMA33

I think I will live with this bug until I change hardware.

Many thanks !

js