AOpen vs BenQ - quality scan

vbimport

#1

i’m just wondering, is the aopen 1648 aap pro dvd-rom totally useless for quality scans? or why is there SUCH a big difference compared to my benq 1620 pro? both drives have the newest firmwares and the disc was written in the benq @ 4x.


#2

Does the burn play or retrieve data without errors? if so then the aopen seems flawed.


#3

When I did a quick comparison last week, there was not much difference between the 2 of them.


#4

the data can be read without problems and the transfer rate looks ok too, so i assume the aopen drive can’t be used for significant quality scans…



#5

Comparing scans made on different readers is almost totally useless. Until the burning technology reaches the point where most readers can read equally well, scans are useful solely for the following:

[ol][li]Comparing identical media on idendical drives with different firmware.
[/li][li]Comparing different media on identical drives with identical firmware.[/ol]
[/li]Anything else except for the above is a waste of time.

It’s trivially easy to find burned discs that scan on the burner with hardly any PIE and zero PIF that DVD players refuse to play and that scans on other drives show as completely rotten. It’s also trivially easy to find discs that give poor scans in the very drive that burned it only to give great scans in another reader. In fact, it’s difficult to find anything except the above - finding two different brands of drives that give similar scans is not easy. At least for DVD. For CD it’s not hard - but the technology is much more mature.


#6

ROM drives are not reliable for PI/PIF scans. That is your problem; you are trying to do something that was not supposed to be done. Some people have been able to fund certain ROM drives that seem to work for them but your experience again proves that this is more often not the case. You also are scanning at 8X. The generally accepted speed is 4X.


#7

with the benq 1620 the convention is to scan at 8x…4x with a liteon. however, in order to conform with the actual official std you should scan at 1x (almost no one does this).


#8

Sorry I wasn’t clear; I was referring to his ROM scan. I never heard of BenQs being run at 8X. I did know that their ecc was different so their threshold for PIF was different. I learn something new every day.


#9

ich will scan the disc once more with the aopen at 1x speed, just for the fun of it :slight_smile:

-andy-


#10

This is an incorrect generalisation.

Only LiteOn Mediatek chipset based DVD-ROM drives have been shown to be unreliable in any way for PIE/PIF scanning, due to their inconsistency.

However, AOpen 1648/AAP has been very consistent.

The only reason the scans are different, is because they are different drives.

An equally valid question to the original poster would be: “Is my BenQ 1620 useless for scanning, because it differs so much from my AOpen DVD-1648/AAP?”. Neither one is “wrong”. They just read differently. The same applies for Toshiba SD-M1802, Plextor 712/716, LiteOn DVDRW burners, Optorite burners, etc.

I’m beginning to think that Erik Deppe should include a compulsory introductory test to CD DVD speed which would explain all this.

We would have a thousand posts less per month here at CD Freaks :slight_smile:

regards,
halcyon

PS To re-iterate: there is no single drive on the consumer market that is “the best” or “only correct” or “most accurate” for dvd PIE/PIF/POF/jitter/beta scanning. All drives just report how they are themselves able to read a particular disc. They do not report errors directly on the disc.