My CD burner tends to be "lacy" a lot. When opening directories and files acts as slow as molasses even giving the efect of freezing Konqueror. This happens after I was testing a boot floppy disk and it failed recognising rightly this hardware. In MDK Control Center I see the CD burner as if it were an SCSI device when actually is an ATAPI one. My CD burner is :Plextor PleXWriter 24/10/40A and it was correctly recognised and configured when installing MDK 9.0 and updating to 9.1. I don't know if this configuration is unrelevant to performances or if I must check more things (I can't figure what and where), or how to fix it. I'll appreciate a lot any advice and indications about where to find information on this topic.

I have that same burner. Your drive is detected as SCSI because SCSI emulation is enabled for that IDE drive. This allows you to burn CDs. I don't think it would be related to your performance problems (I have none, and I use IDE-SCSI), but you could try disabling it.

Thanks Zombie for your quick answer.
More information on the same problem: Surprisingly with Knoppix my CD burner does not appears to be a lacy one, indeed it accelerates very quickly and in Konqueror shows quite fast all directories and files, even the execution of programs goes smoothly. In Mandrake it offers less than optimal performances, is sluggish, partially accelerates only after a very long "latency" period, lets say half a minute, it freezes all programs trying to work with it. In MDK Control C. it seems to be correctly configurated under SCSI emulation as Zombie wrote before, and I think it points to the correct device: ‎/dev/scsi/host0/bus0/target0/lun0/cd, but also appears an older configuration: /dev/scd0, but I checked this scd0 and it also points to /dev/scsi/host0/bus0/target0/lun0/cd. I can't figure where to find where is the problem, but I'm convinced that it is not a hardware problem but a configuration one, as good performances with Knoppix demonstrates. I'll appreciate so much every idea, I'll test everything and I'll post results. Thanks!

Do you have supermount enabled for this drive? I had similar problems with my drive using supermount (automatically mounts CDs). Maybe there's a problem with supermount and IDE-SCSI?

Oops! It appears to be a non-related supermount problem(I tried with and without enabled supermount). The more I analyze this issue the more I'm becoming prone to think it is a hardware-related one. Indeed I'm finding this "lazy" behavior occurs only with some of my CD's! getting full performance with others, i.e. the Knoppix CD. Do you know if it exists some software to test the performances of CD reader devices?. Anyway thnxs a lot!

You mean that even when you put in the knoppix cd while running mandrake, the cd drive seems fine? If so, would that not indicate that you have a bunch of bad cds?

Yes quatsch. You described the situation. And now I'm determining the reach of this cathastrophe. But I'm optimistic because I have only burned very few CD's of this batch (I never had to change of brand). Thanks for your help.