How to fix Optical Drive slow reading CDs - Dell XPS17 Xubuntu 18.04.2

Ask Ubuntu Asked by user94924 on September 6, 2020

My Dell XPS17 has been running OK with 16.04 and has recently done the upgrade to 18.04.2. The CD/DVD drive worked fine on 16.04 to the extent that this was the device of choice for recording and copying CDs and DVDs. But on 18.04 It records CDs/DVDs OK and reads DVDs, but is glacially slow when reading CDs.

CD-Rs and DVD-Rs record at around 2-3MB/s and 3-4MB/s respectively but I noticed that Brasero was taking a longer to compute the checksum for CDs than for DVDs. Doing a test, I found reading back a CD-R takes about 19 minutes for 710MB at 600KB/s, while the same CD took less than 5 mins to record. Using an external Dell USB2 CD/DVD reader the same disc reads in 4 mins at 1.5MB/s. On the other hand Recording and reading back DVDs seems to be OK with a read speed of around 4.7MB/s.

There’s a Win10 system on the same box and I found that the DVD performance was much the same as with Linux, while the CD read speed began at 600KB/s quickly building to 2.5MB/s and completing the operation in around 4 mins for 710MB.

I’ve tried to look at the settings and as far as I can tell DMA is enabled so I’m a bit foxed.

The optical drive is a Toshiba Samsung 12.7T SATA DVD+/-RW 8X and the CPU is a series 2 core-i7 with 8GB memory and 2 x 500GB HDDs with plenty of space.

It appears to be a CD read problem. It doesn’t matter where or how the CD was cut, Windows, MAC, Ubuntu, or commercial ROM. Doing some more tests I discovered the problem arises when I move to 18.04.2 either via the upgrade process or a clean out-of-the-box install, the only customisation being to add seconds to the panel clock. Thunar takes 20 mins (5 times as long as on 16.04) to copy a 710MB test CD but only 4mins 20 secs for a 2GB DVD at 6 -> 8MB/s.

I’d appreciate any help or pointers as to how I might solve this issue.

Tks in anticipation

2 Answers

I also posted this on where I think the problem has been isolated. It seems that current versions of Brasero write a bad block at the end of recording and the new distro (18.04) sees this and sets the drive speed to min, ie 4x. Earlier versions of Ubuntu ignored the error.


Correct answer by user94924 on September 6, 2020

The problem lies with Brasero as in my previous post. It writes a bad block at the end of TAO (Track At Once) recording. When reading a CD, if Ubuntu 18.04 encounters a bad block, it sets the drive speed to slowest (ie 4x). It should reset it afterwards but doesn't. I don't know how it deals with an external CD/DVD drive as I've not tested it. The work around is to use Xfburn and record SAO (Session At Once) or Xorriso. I don't know if it's been fixed in 20.04 as I now no longer use Brasero. By far the best software is Xorriso but it's a bit complicated for everyday use, so I use Xfburn via the GUI. The detail is all here:
Hope this is helpful jg

Answered by user94924 on September 6, 2020

Add your own answers!

Ask a Question

Get help from others!

© 2024 All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP