CD-DVD Speed's "Quality score"

How much weight should one place on CD-DVD Speed’s “Quality score”? Say everything else looks fine as per the “Interpreting PI/PO error scans thread”…

What if you get a Quality score of 68 but all other parameters (PI (Parity Inner) and PO (Parity Outer)) as measured by Nero’s CD-DVD Speed sound good or even great? Any reason for concern?

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It depends…

I don’t use the Quality Score myself, preferring instead to interpret the graphs and the numbers directly. The Quality Score is derived only from the maximum PIF value, the scanning interval (e.g. 1 or 8 ECC) and POF if the drive can report POF.

It would be much easier to comment on a specific scan rather than commenting blindly without knowing anything about burning drive, scanning drive and other information.

Well if you had one disc with a singular spike of 10 and low PIF throughout the rest, VS a disc with only 2 PIF max but a fat block of 2 PIF that causes 2000 PIF in a small area, then you’d totally have to refute the quality score since the disc with a single PIF spike might not cause any problems, whereas the disc with a block of PIF would have a much greater chance of causing playback problems.

IMO, quality score means nothing. It’s merely based on whatever the max PIF is, which is a very bad way to evaluate quality.

Alright, thanks for the replies. I certainly have a better idea now. :bow:

Personally I wouldn’t go as far as calling it “very bad”, as there are far worse ways around :wink: - I’d call it “disputable” and “very approximative”.

Honestly, I’ve seen much worse! :doh:

But I agree with you guys, interpretation from experience and cross-checking, while taking into account the drive used as a scanner, the scanning speed etc… can’t be replaced by any “quality score”.

Same here. :slight_smile:

As I started to read this thread, I thought of a disk I not long checked with just that, a very good PIF count spread, but a large’ish single spike that drops the % to 30~40. But I have no problems with the disk at all, and would bet that it will play and last longer than many a 80%+ with a solid 2 PIF block on the disk.

The numbers are ok for a quick idea, but when you learn to read the scan it will fall into place. I can now see the scan and if a problem know what to look for on the surface …dust or other things that get on the disk and block, or refract the laser that you can blow away and see the unchanged dye to a scratch.

There’s really no such thing as a DVD with a solid 2 PIF block on the disc - that’s only the result of the limitation of the CDSpeed graph where every horizontal pixel corresponds to approximately 350 ECC blocks. If there really was a solid 2 PIF block (in a 1 ECC scan), there would be more than 280,000 PIF on the whole disc, or 700 PIF per 1 pixel width on the graph.

(This assumes standard size of CDSpeed window)

I guess the reason [B]Erik Deppe[/B] chose to use only PIF maximum value for QS as it is the only reportable parameter which can be useful across all the drives supported by CD-DVD speed.

AQS is a better system but still can be skewed by spikes.

This makes sense… let’s not forget, indeed, that many drives that we don’t consider on this board as “reliable” scanners are nevertheless supported by CDSpeed. :iagree:

The thing that really bothers me in CDSpeed is not the “quality score” feature, but the “disc quality” labelling of the scanning feature… sounds to newbies as if the burner & reader didn’t take any part in the scanning results, and that it is possible to measure “disc quality” with a simple homemade PIE/PIF scan…!

Haha, that’s funny you should say that because I was thinking the exact same thing in my head. Why not just call it PIE/PIF error testing or something? Quality scanning lol… misleading to the extreme, even fools people who are not really newbies :stuck_out_tongue: