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PowerREC on:


PowerREC off:


The disc is a RICOH 8x +R (ricohjpn-r02-03), on a 50pcs spindle, branded as Ricoh. Write speed was 12x in a Plextor 716 TLA#0202, Fw 104. The (not so) funny thing is that the disc gets unreadable when PowerREC is ON exactly at the point where it reduces write speed. This also happens with genuine Taiyo Yuden 8x -R (Plextor label).

Shouldn't it be the other way around??

I think you should contact plextor and some german media since I think there are some people out there who like to know.
hmm knoweing how powerrec is supposed to work. I can say that they probally have a bug in the firmware causeing this behaviour.

Another one, this time with plextor branded taiyo yuden 8x -r media, written at 12x

pr off:


pr on:

actually this is very funny

It is not Especially, one of those TY 8x -R discs was 1,60€

well.. your purse has my sypmathy.
but i still think it's funny how PoweRec fucked up! big time!!!

You're not the only one complaining about issues with TY media. I personally have not any issues, but I've seen similar comments at CD Freaks. By now we should all know that PoweRec isn't perfect.

The media is fine (as you can see at the read curve)... the error rate for the ty 8x -r @ 12x disc with powerrec off is also good (pisum8 max = 25, pif max = 2, pif total = 500)

What are the error rates like with it on?

As you can see, the disc is unreadable with PowerRec ON. The location where PowerREC reduced the speed the 2nd time is exactly the location where the Toshiba drive can't read the disc. The first spindown is the first reduction of write speed.... as if the progress of reducing write speed screws up the disc.

I'll try to scan that disc

Wow!
Pretty scary.
Like you said, it should be the [exact] opposite!!

Possibly On = Off ? and Off = On? LOL!

The error rate on the TY disc recorded with PowerREC is ok. It really seems the writer is doing something to the discs the Toshiba drive doesn't like

Hmm try the followeing force one serious buffer underun and try to read that disc with Toshiba.
To see if it has problems with reading gaps on dvd media.

I have the problem:

An MCC-003-00 disc shows a strong change in asymetry at around 350 MB, and exactly there it has a severe read speed reduction in the Toshiba drive (PR off this time!)

It is known that Toshiba readers are very bad at reading badly written weak sectors on CDs, which is nothing else than bad asymetry. So this problem with Toshiba drives seems to be there for DVDs as well When power rec kicks in, it seems that the change in the asymetry makes the Toshiba drive fail to read that area.

Too bad this can't be the only problem, as I don't see such a change in asymetrie in the taiyo yuden disc that doesn't work

...

Hmm seems to me that that measurement is in the standards.
Seems that Toshiba is to blame and not plextor in this case. Still on the other hand this behaviour shouldn't be expected when Power rec kicks in correctly.

Hmm wonder what some of the other parameters look like at that spot !

PIsum8 is ok, PIF has one single spike of 7, meaning that the plextor itself also has an issue there, though not as bad as the toshiba

The values itself are ok for Beta, but the *change* in beta is too large. The Toshiba drive seems to be allergic to several jumps in asymetrie within a short range

Got any Benq 1620 over there. If the answer is yes what does jitter do at that spot or is it not possible to check at single spot.
(Me still haveing just a poor good old Pioneer 106D)

I don't have any Benq here, but the plextor doesn't report anything special about jitter there. Too bad it doens't have a real scale for jitter
source file

hmm just was reading ECMA -349 page 76.
Isn't the issue we are seeing here a
Normalized Slicing Level jump ?
30.2.4.
I think it could be but then again I might be wrong.