Quality Test : cause of drops in read speed?

[ItalianJob]

Hi,

My BenQ 1620 B7V9 (not hacked) starts to show regular drops in read speed during PI/PIF tests.

a) Fuji DVD+R 8X (YUDEN000 T02) @12X WOPC ON (6mn45s after QScan 1.1)
Nero Burning ROM 6.6.0.14

Note the reading speed drops in green...

b) Maxell DVD+R 4X burned @8X WOPC OFF.
Nero Burning ROM 6.6.0.14

Note the reading speed drops in green again...

Also, I have very low quality issue with 12X WOPC off on many good media (MCC 003, YUDEN T02, TG02...). Enormous PI spikes @2 Gb and big PIF spikes. In the first days, all was good or better, if I remember well...

What can be the cause of this ?

I run XP SP2 and my BenQ is in master secondary, with a slave Toshiba DVD-ROM. Everything is in UDMA 5 (HDD) and UDMA 2 (DVD drives).
Got a 60Gb hard drive, with no errors at the moment...

I'm thinking to :
1/ take off my Toshiba slave device.
2/ uninstall IDE channels and reboot
3/ flash again. My BenQ 1620 was originaly in B7U9, and I flash with official B7V9 from BenQ site with no hack.
I read some stories about flashing back to B7T9 and then B7V9...
But ?

4/ Buy a news hard drive, a new power supply, a new case or a LG ?
Not my wish... :bigsmile:

[max_clif]

Uh, you're burning 8x media at 12x and then seem puzzled why it is not giving you good readback speeds?

Not to mention you're using crappy fuji discs that are now known to have quality issues.

This isnt a hardware failure. I too get these problems using the same burner, same sh!t fuji discs. Burn at 8x and problem goes away.

[Sapa]

Due you have a clue what the drops in reading curve mean ?
Thanks for sharing

[Sapa]

OK, here is the explanation or absence thereon for the mysterious, randomly occurring behaviour.

http://club.cdfreaks.com/showthread.php?t=132864&highlight=drops+read

[ItalianJob]

Thanks Sapa and Haxel@hardware.fr.

I will post my experiments too...

[ItalianJob]

It seems my problem is solved =) I'm doing some new scans, stay tuned...

[ItalianJob]

Not 100% solved, shit !

[max_clif]

OK, here is the explanation or absence thereon for the mysterious, randomly occurring behaviour.

http://club.cdfreaks.com/showthread.php?t=132864&highlight=drops+read

That thread answers nothing about the problem.

Question: if he burns at 8x on 8x will problem go away. If yes, then it isnt really a configuration or burner/hd problem is it.

[Sapa]

Other poeple burn those media at 12X or 16X and don't have the "problem".
If you do, oe anybody else does, a quality scan at 16X, you would systematically that saw-like pattern.

I think there is no real problem either getting that pattern or burning at 12X those media if they prove to be well burned using other applications or readers. The scores as shown above are by no means indicative of bad burns.

Just that the "intelligence" in WOPC dictates the behaviour in some circumstances. The unanswered question is : which circumstances ?

[ItalianJob]

Question: if he burns at 8x on 8x will problem go away.

12X overspeed is official on MCC003 and 16X overspeed is official on YUDEN000 T02. My Fuji are the best discs I ever had. Most people, including me, have better results burning @12X those 8X certified media than burning them @8X (lower total PI/PIF, lower max PI/PIF) when they are grade A, not Datawrite MCC003 :bigsmile: .

Seems I had two problems :
1- a quality issue, that seems solved with reflashing as said in the BenQ FAQ
andn maybe by other tips (described in my first post).

Verbatim DVD+R 8X@12X WOPC OFF

2- The speed drop problem, that went away for a few scan, and is here again (see the Verbatim MCC 003 scan in 1/)

Sometimes its not :
Datawrite MCC003 8X@12X WOPC ON

Datawrite MCC003 8X@12X WOPC OFF


My Datawrite MCC003 are from a poor spindle. No luck. Some have very good ones... I use them as test discs :bigsmile:

AS SAID :
A 16X scan seems to show this drops, so I think it's an internal behaviour, I cannot cope with... Nothing bad, I hope.

[Chuck44]

...The speed drop problem, that went away for a few scan, and is here again (see the Verbatim MCC 003 scan in 1/)

FWIW, my 1620 has always had that speed drop while doing quality scans, except for a couple of times, which I can't explain. I would guess it's normal behavior.

[crossg]

Mine does the same thing once in a while. Haven't figured it out.

[ItalianJob]

Thanks, guys

[Pork_Chop]

That has happened to me many times on a few types of discs ( Maxell002, RitekG04, Optodisc 0R8) and I could never find a common cause. All were burned at the rated speed. I get at least a single dip at ~150MB on just about every disc I burn.

[ItalianJob]

For the quality problem on several media, all is better now (after a few operation describe in my first post : no slave, firmware re-flashing, etc.).

Verbatim DVD-R Pastel 8X@12X WOPC ON.
Nero Burning ROM 6.6.0.14

[jk736]

The same issue comes, and the same conclusions emerge.
The two mysteries are:
1) It suddenly appears and then disappears (even without any configuration change)
2) Some people see it more, while some people never observe it but nobody found a grand unification theory that explains everything.

[ninbang]

Just today (gone for a week but had my 1620 for abt 3 weeks now), my scans were showing BOTH drops and spikes in read speeds during Quality Scan in CD-DVD Speed v4.0.0 (same thing when scanned with v3.8.0). Even when scanning a burn from earlier this month, I still get those read spikes & drops (though the original scan taken after the actual burn showed a smooth line).

The spikes / drops are more prevalent towards the end, but still occur all throughout the scan. The scan speed is set @ 8x, yet the read speed drops to 6x then jumps to 12x in immediate succession towards the end. Average spread is about 4x dip to spike peppered through the burn.

I haven't rebooted for about 10 hours today, and my harddrive was being written to while scanning. I just wonder if the BENQ 1620 may be sensitive to sharing cpu resources with other apps. Maybe just enough to cause the inconsistent read speeds during the scan.

[ElliotW]

Somebody explained that it is not a "drop" in the read spead, but rather a complete (but short) pause in the transfer of data from the reader. This seems correct to me as the "totals" completely stop climbing for this instant. That is they don't slowly climb - they stop, then resume. My spikes go away (not that I get them that often) if I leave the drive alone for 15 minutes or so. Maybe it's heat related?

[ItalianJob]

ElliotW > A heat related problem ? I don't know, I will check temperatures with Asus PC Probe when it happens.

[ElliotW]

We don't a funny reply, but I don't know where you would actually stick the Asus Probe? My BenQ's case never seems to get too warm.