BenQ DW1620 - questions about error scanning and defects

vbimport

#1

I posted this in the BenQ forum because it’s mostly about the 1620.

I’ve had a Pioneer A06 and A07 drive for a long time. I finally bought a BenQ DW1620 (firmware B7U9) for error scanning, and just for fun a I bought BTC 1016IM (firmware A07R) to see how it compared. I’ve used 2 different $20 BTC BDV 316E reader drives and they were good, but the last 2 I bought were bad on arrival (not quite DOA but they couldn’t reliably read DVDs), so for $14 more I figured I might as well try the 1016IM instead.

I read the posts about interpreting PI/PO scans, so I think I understand the basics. I’m using the latest Nero CD-DVD Speed 3.80. My first goal is to make sure these drives are behaving as expected and don’t have any hardware defects that would require me to return them because my return period expires soon. I’ve read many threads here and on Videohelp, and I could not find the answers to these questions (it doesn’t mean the answers aren’t there… just that I couldn’t find them). Here are the questions:

#1. How much variation in PIE and PIF between scans should I expect if I scan the same disc on the same drive (BenQ or BTC)? I just want a rough guess… 10%, 20%, etc. I realize no 2 scans will be exactly the same, but they should be close? For instance, if I scan a disc and get PIE averaging 15 and scan it again on the same drive and get PIE averaging 40 should I be worried that the drive is bad?

#2. How much variation in the PIE and PIF between scans should I expect when I compare a scan of the same disc between different drives (BenQ or BTC)? I realize the numbers have to be scaled to be comparable, but aside from that should the graphs always follow the same pattern or is it OK for there to be spikes on one and not the other or for the shape to be different?

#3. If the same media burned on the same drive at the same speed occasionally shows a huge difference in PIE and PIF (including some PO failures) on a particular disc, yet both disc surfaces when examined under a light look identical and defect-free, what does this mean? For instance, does it mean this particular disc has bad dye underneath or the burner did a bad burn job on this particular disc for some unknown reason?

#4. Is it normal for all error scans to start out at half the maximum speed and work their way linearly up to the maximum speed at the end? Is a brief but sharp drop in speed at roughly 100 MB normal for a BenQ 1620?

#5. Should I be concerned that the BTC 1016IM in Nero’s speed test takes almost 50 seconds to recognize certain recorded media compared to the BenQ’s 5 seconds and that pressed media (such as a CDROM) sometimes fails during the spin-up/spin-down portion of the speed test?

#6. Using the same disc, the Nero speed test shows both the BenQ and BTC speed starts at 3.5x and goes to 8.3x. Is this normal for them not to achieve their maximum read speeds in this test?

#7. 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.

#8. If a disc has a large PIE count (in the 80-200 range) but its PIF looks very good, what conclusion can I draw from that? I see rather high PIE on 1x RITEKG03 discs burned at 1x. Does the high PIE count mean RITEKG03 isn’t as good as I thought, do 1x burns often have high PIE, or is there another explanation why older, slower media has higher PIE but its PIF looks good?

#9. 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 corresponding to this flaw, but I saw nothing special. I then took a 8x MXLRG03 disc which had significant scratches and purposefully put a thumbprint on it and then burned it at 4x on the BenQ. The error scans on both the BenQ and BTC look very good with no spikes. In fact, the PIE was very low (under 20). Does this mean that defects on the surface have to be huge in size to make any impact on the error scans or is there another explanation (such as the error scans not being 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 that’s a waste of time. Perhaps large specks are insignificant to PI/PO even when burned at high speed?

I haven’t finished my scanning tests, and I’ve barely started burning. I already had some byte comparison errors on a BenQ burn, but I’m not ready to blame it yet (it could be the HD and ATA100 issues).

I read various BenQ threads trying to see what the common hardware problems were, and it seemed the problems were either a totally dead drive, disc eject problems, or problems burning certain media. I didn’t see anything along the lines that a bad BenQ would give misleading error scans or inject occasional data errors into burned media.

Any help would be appreciated. Thanks.


#2

For my future benefit, can anyone tell me why no one has replied:

  • Nobody knows the answers to my questions.
  • My post was too long and nobody wants to read that much (i.e. I should break future posts into smaller pieces).
  • I’m a newbie.
  • People thought my questions were dumb and didn’t deserve to be answered. (After searching the forum I only found the answers to #4 through #6, but the rest still elude me so most of them don’t seem like dumb questions to me.)
  • The BenQ forum is not the right place for these questions.
  • Some other reason?

I would’ve edited my original post, but the option to edit is not available to me.


#3

first off is ignore speed3.80 quality number it means nothing look at graphs if the pie graph is under 280 and pif is in green zone your burn is good, lower pie is better but under 280 is what you want most of my benQ scans with speed3.80 are pie under 50 usually under 20 and pif is usually under 16 usually about 5 or less.

PS one or two spikes on pif past green mean nothing but will send the quality number out to lunch thats why need to only look at graphs and ignore one of two lone spikes in pif that go over green zone if get any


#4

I can answer some.

The number and distribution of PIFs should be almost identical, ±1 or 2 in individual values, ± maybe 10% in the total number. PIEs will vary a little more from scan to scan (I’ve seen >30% differences) due to different disc alignment, temperature, etc., but the general shapes, slopes, and other PIE patterns should be similar.

Much more variation. Large defects should be recognizable in both scans, otherwise there are too many differences between optical and ECC (error-correcting) performance of two different drives to make any meaningful comparisons.

Yes, the varying speed is normal CAV (constant angular velocity) reading. The spindown around 130 MB is always there, in all 1620s.

There is a scanning speed selector in the quality test window of CD-DVD Speed that allows you to scan (on the 1620) at 12x and 16x CAV, but 12x and 16x scanning is problematic due to multiple spindowns and their effects on the results.

Ritek media always had high PIE levels, nothing unusual there.

You can’t miss a black dot on a quality scan. Here are three scans from an experiment I just did.

The first scan is a freshly burned disc.

The second scan is the same disc with three black dots, about 0.5 mm, 1 mm, and 1.5 mm in diameter, made with a black Sharpie pen using quick-drying, alcohol-based ink. You can easily tell how they were arranged by looking at the scan. The DVD error-correction system, called RSPC (Reed-Solomon product code) can compensate for up to 7.1 mm of missing or damaged track data, so it has no problem reading through my dots.

The third scan is the same disc after I wiped the dots off with a tissue soaked in alcohol. Compare scans 1 and 3 to see the normal variations between scans of the same disc in the same drive.

(Scans 2 and 3 are partial scans, manually stopped after 0.5 GB.)


#5

Agent009, thanks for the helpful reply and those scans! I’m sorry I didn’t check for your reply sooner.

#1. I guess my PIF and PIE count variation between scans on the same drive is within acceptable limits. I’d see a max PIF of 4 and then next scan it would be 6, or if the max PIF is 6 it would be 8 on the next scan (which is higher than a 10% variation). The PIE is usually within 10% of each scan. What threw me off is that I got some spikes which rescaled the graphs, but the PIE averages were actually very close. One of my scans showed a solid block of PIFs at 7, but on my rescan it was no longer there… it must’ve been a piece of dirt that blew off.

#8. You mentioned that Ritek (such as the 1x RITEKG03) has always had high PIE levels. Would you happen to know or have any guess why? I’m still trying to understand how 2 discs by different manufacturers with identical looking surfaces (i.e. clean and no defects) burned at the same speed on the same drive can yield an average PIE count of 10 on one disc vs. an average PIE of 50-100 on the other disc. Is that indicating that the disc with a higher average PIE (even though it’s within specs to be considered a “good” disc) is of poor quality or that the writer is not good at burning it?

Since you said Ritek has always had high PIE, that would indicate it’s not the brand of burner that is to blame. Also given that the PIE count is relatively constant on Ritek media with very clean surfaces (some of the cleanest in my opinion), I assume there are no microscopic specks or defects causing the high PIE. Therefore, I assume it must be the Ritek dye. Well, the bottomline is I hope higher PIE is not indicative of a shorter shelf life for Ritek. I used to think that slower 1x burns should be more reliable and error free, but these error scans shoot my old theory to pieces.

#9. I must not have made my black “test dot” big enough because I saw no easily distinguishable error patterns like your scans showed. Apparently the large scratch also on the same disc which showed a discoloration after it was burned didn’t impact the error scan either. I guess a scratch is less damaging than a black line of the same width. I should measure the dots next time.

Finally, do you think anyone would be interested in seeing a few of my error scans, or is the general consensus not to clutter up the BenQ 1620 error scan thread with more scans of the same media?

(P.S. Thanks KenW for your reply too.)


#6

ah, but what u should do is take that same disc, and make 1-2 scans of it each day. Over a period of 3 weeks see if the results dont get any worse on that same disc.

I did that and found the graphical results varied widely for the PIF, and for PIE I saw a 50% difference for scans days apart.

The main thing is that the burns are all around 95% range with read back speed little or no spikes. That’s how I evaluate my burns.


#7

Sapo… I for one have asked myself the same questions you have posted here. I burn over 1000 DVDs each year (on BenQ models) and try to make a mental note as to what works and what does not. I have found that finger prints will cause a bad burn. Ritek (as agent009 said) always has high PIE counts but rarely is defective. I did get a batch of Ritek DVD +R that had blemishes after they burned. These were defective and scanned very bad with Nero. My return rate a few years ago using HP DVD300i and Pioneer models was about 5-10%. This does not mean they were defective, just that the customer could not play them. This year with over 1000 already shipped the return rate is less than 1%. The point is…DVD players. media and BenQ burners are getting better. I primarily use Taiyo Yuden 8X -R but when I have used other types of media, there is no real problem with playback on the majority of the consumer models being sold today. Now that TAiyo Yuden can be purchased for under .50cents each, there is no need for me to use anything else. I am addicted to Nero CD/DVD speed check and watch it carefully just to see how the burns are going, but it is getting to the point that it is not needed once you find what works for you. Thanks for asking the Questions!