quote:

---

rjw: "First there's a difference in Plextor c2 and Lite On c2."
[\quote]

That's possible, even probable. I don't think there's public information available as to how LiteOn/KProbe classify bit-level errors into C1 and C2.

quote:

---

Well
C1/C2/CU are drive dependant. So disc behaviour in different drives cause different error rates.

---

Agreed.

quote:

---

Now at lower speeds this extra behaviour isn't allmost there. For this reason the audiodev CATS analyzers meassures at 1x.

---

Yes, drive dependence is diminished as optimal read speed (usually 1x) is approached.

quote:

---

About Plextor vs Audiodev CATS analyzer I should post the results over here in a couple of days.(the Ct' article.)

---

That would be very nice of you. Also, any additional information as well would be more than welcome as I'm far from being an expert on the issue.

quote:

---

But why did you recommend high speed reading a couple of posts ago for cd docter

---

Did I? I usually try to recommend a lower speed as a true measure of what might be a better indication of what the quality of the disc is.

However, if you plan on using the disc to be tested on the same drive on which you test it, then it makes sense to test at a higher speed (even on max speed), because it simulates real life usage situation that the disc/drive combo will have to face in the future.

So, to clarify my stance if I've badly expressed it before:

- slow test speed is usually a better indication of the drive independent media performance (if an indication of anything at all)

- higher test speed is usually a better practical measure of real-life performance for the test drive / test disc combination under scrutiny, because discs are often read at a higher speed on normal usage

quote:


High speed measurement can explain the behaviour of the disc you normally can expect on high speed reading with most drives.

---

This is where I partially disagree :)

I think my results show (if correct) that not even a slow test read speed is a guarantee of read performance on another (different maker/model) drive.

Results cannot be generalised from the test drive to another drive, regardless of what the test speed is.

If they were generalisable, then LiteOn/Kprobe and Premium/PlexTools results would be at the very minimum in the same order of magnitude or even better, in a statistically insignificant variance levels.

My tests (again, if correct) show that this is not the case.

The higher the test speed, the less there is correlation with test results and actual high speed 'normal usage' read results _on a different drive_.

I think if you want to test drive compatibility at high speed, you need to test it with the drive you want compatibility with OR you need a test drive from the results of which you can generalise over a larger population of other drives (a dedicated testing platform perhaps?)

I don't think either LiteOn/Kprobe or Plextor/PlexTools combo results have been yet shown to be reliable indicators of media read performance (error counts or even read speed) on OTHER DRIVES except the one on which it was tested.

The only test result showing real-life correlation with a calibrated test gear has been the C'T article. That's why I'm really interested in that article and trying to understand if the Plextor or LiteOn results are to be trusted _EVEN ROUGHLY_ (for any other drive model except on which the test was done).

If anybody has both drives, please do some tests also and contribute comparative results here.

Why am I interested in this? Various reasons:

- I will plan on archiving stuff on CD-Rs that I will want to function years from now (yes, I already have stuff from mid-90's that works well when handled/stored properly)

- In the future it is very UNlikely that I will use the same drives to read these media as I burned/tested them with.

- As such, I need a roughly useful measure of burn quality based on which I can select a media/drive combo that I hope to produce READABLE discs for a wide variety of drives in the future too.

So my needs are practical and not merely academic. Yes, I could in theory archive the burner along with the media, but I think this is a little bit impractical.

regards,
Halcyon

quote:

---

But why did you recommend high speed reading a couple of posts ago for cd docter

---