BenQ DW1620 PIE/PIF error scans - questions about my results

[Ronaldus]

After the last discussion about which drives support PI/PO error scanning, I decided to buy a BenQ DW1620. I've done dozens of error scans on different types of media burned by my Pioneer A06 and A07 drives (with old firmware) at various speeds.

Overall, most of my scans showed very good burns (well within specs), but there were a few exceptions. Also, on CD Freaks I read that some people have gotten defective BenQ 1620 drives, but I couldn't find any specifics of the defects other than DOA, eject problems, or unable to burn anything. My first concern is to make sure that my BenQ is behaving properly before my 30 day exchange period is over. Is there anything special I should test on my BenQ besides error scanning and burning?

My BenQ 1620 came with firmware B7U9 (which I haven't yet updated because I haven't had time to research which firmware version would be best for me... feel free to make suggestions). I'm using Nero CD-DVD Speed 3.80 running all scans at 8x.

#1. The same disc scanned on the BenQ multiple times gives results that are very close to each other in shape, but sometimes the PIF will have a maximum of 4 and other times it'll be 6 (that's a 50% difference). A few times PIE will be 20-40 and the next scan it'll be 30-50. Steve2713 told me the variation should probably be within 5%, but mine sometimes exceeds that. Can any owners of the BenQ 1620 (or similar models) tell me what sort of variation in PIE and PIF you see on the same disc scanned multiple times in the same drive?

#2. I found that most media burned at any speed from 1x to 4x on either the A06 or A07 had occasional PIF maximums in the 2-6 range and jitter around 9%. With a few exceptions the only difference between different media types, different speeds, and the A06 vs. A07 was the PIE (and the density of the PIF). For instance, RITEKG03 burned at 1x usually had a max PIE around 50, while TY burned at 2x or 4x had a max PIE around 15. TTG02 burned at 2x had a max PIE over 1000, but burned at 4x a max PIE under 100. ProdiscF01 was the opposite of TTG02 (slower burns were better). It's on my to-do list to compare my scans with ones on CD Freaks assuming I can locate scans of the same media burned at the same speed on the same drive scanned by a BenQ 1620.

#3. Given that the main difference between the media I scanned is in the PIE, does anyone know what a high PIE means in terms of the real world? Does it indicate a particular physical characteristic of the media, dye, or drive, or is it meaningless? My theory/guess is that high PIE means that the burn marks are not ideally shaped causing a large (and nearly constant) amount of correctable errors throughout as occasional burn marks are misinterpreted. I can't imagine that invisible dust specks could account for a high PIE across the disc. If this guess is correct, that means the dye in TTG02 was optimized for faster burns and ProdiscF01 was optimized for slower burns, at least on the Pioneer. I assume that PIE near 50 on the average RITEKG03 discs shouldn't cause me to worry about their longevity but merely indicates my Pioneer drives are not as well optimized for burning them at 1x as they are for TY at 2x or 4x?

#4. For BenQ 1620 owners: Is it normal for all error scans to start out at half the maximum speed (about 3.5x) and work their way linearly up to the maximum speed (8x for me) at the end? Also, it it normal for there to be a brief but sharp drop in speed at roughly 100-200 MB on every BenQ 1620 error scan? Instead of being a perfectly straight speed line there's a big glitch at the beginning usually accompanied by a spike in PIE and PIF.

#5. When scanning some pressed DVDs for fun, should I be concerned that a few of them were unable to scan beyond the first layer and a couple of them failed with an error like "No sense indication (000)"? No scans of recorded media have failed yet. Could this be due to some sort of protection?

#6. I took a thin-tipped black Sharpie marker and put a dot on an already recorded disc's surface and then error scanned it. I expected to see a spike in PIE and PIF somewhere due to this flaw, but I saw nothing special. I then took a 8x MXLRG03 disc which had significant scratches and purposefully put a large thumbprint on it and then burned it at 4x on the BenQ. The error scan of this disc looks very good with no spikes, and the PIE was very low (under 20). Does this mean that defects on the surface have to be utterly huge in size to make any impact on the error scans or could it be my error scans are not reliable? In the past I've always inspected each disc's surface before burning and used compressed air to remove dust, but these tests are making me think only very large flaws are worth worrying about regardless what speed the disc is burned at. Do people agree?

I would appreciate any help or comments. I can post some error scans if people want to see a few of mine, but I'm under the impression that posting error scans is frowned on at Videohelp. Also, I'm not finished assembling my scans or collecting data. I can post a summary of my results if anyone is interested.

[blackmagic]

Wow thats a big post. Can't answer all of it but i can help you with point four. My benq does the same at the start of the error scans, i'd just ignore it as i think its just a read error in the same spot nearly every time. This never seems to show on any other drives and if you do a straight read scan the drive should read the disc perfectly.