Hi, first i must say my experience with benq 1640 wasn´t very pleasant so far,
I bought a Benq 1640 about a month ago and it came with a defect which made the burner make an awful noise and vibration just when the tray closed and the discs started to be read, apart from that the burner seemed to function properly and since i needed to backup a lot of data urgently i burned a pack of 10 Verbatim DVD´s before i taked it to the official Benq service, it surprised me the awsome quality of these burns, it was a shame for me that the drive had this defect. After taking it to Benq´s official service, i waited more than a week to have the burner back, they said they had calibrated and cleaned the drive and that it was in perfect conditions, of course i didn´t have to pay since it has 1 year warranty, back home i tested it and again i received a bad surprise, the drive had exactly the same defect! , the next day i took it back to Benq, again i waited more than a week and finally they replaced the drive for another benq1640(exactly the same model and even manufacturing date), fortunately this new drive doesn´t have any perceptible defect so far . The point is that after burning the same Verbatim Discs (MCC 003), at the same speed with the same firmware, same system, i found out that the discs quality was not as good as with the previous burner, i suppose nothing to worry about but they show a lot more pi failures, 2 things changed: 1- The burner 2- the pack of DVD, unfortunately i don´t have DVDs from the first pack to test but i checked the disc quality of the first DVDs with the second burner and they all also show a remarkable better quality, my question is: why does the discs quality vary this much? is the new pack of DVDs or the new burner that makes the quality change?, can a burner being exactly the same model vary its performance this much?
Thanks all and forgive my english

Do you know what firmware the two drives had? Two diffrent firmwares could easilly change how well a particular media burns. Beyond that I would say it is probably just variations between drives (firmware is more liklly though). Thats why why there is no perfect drive/media/firmware combination. You just have to try diffrent firmwares till you get one that likes several good medias and there is no perfect media, you just have to find what your drive likes. Your odds are of course much higher with quality media though.

Both drives came with firmware BSJB, after a few burns i flashed the firmware to BSLB (on both drives), and there was no considerable change in any of the drives with this media, what really surprised me is that exactly the same drives (benq 1640 even the same manufacturing date and place) and exactly the same DVDs (Verbatim MCC 003 only different packs) returned pretty different discs quality, maybe i could try flashing this new drive to BSOB but i don´t think there will be much difference

On the other hand you should test the disc quality with the same drive, the one you own now, previous tests done with the previous drive may lead to slightly different results due to differences in reporting errors by each drive.

Even in mass production (same plant, same line, same mfg date) every drive is different.
This mainly due calibration done at production line.

Flashing the drive to "newer" firmware doesn't change this.

Happy burning.

Yes, as i tried to explain in my first post i tested the discs quality with the first burner (which returned outstanding quality) and now with the new burner with similar results, of course i made all quality tests now with the new burner since the first was replaced

You might be right, but this fact makes me doubt now a lot about all reviews of the drives, i mean if there is so much difference between drives of the same model the reviews and other articles about one model lose pretty much their worth

I'm guessing it is just variation between drives. In a lot of cases, if a certain drive and firmware likes a certain (high quality) media, its going to like it for most users, but I have seen instances where it didn't. I have two friends that used to work with me and I built computers for them both (now one works at best buy and the other at frys cause I got them into computers, both sold furniture at the store I work at before). So they both got benq 1620 burners, and I warned them about the high defective rate, and said the alternative was try to find a 3500 or get a 3520 that was having firmware problems (that had just been fixed but just and not that tested). So one got a 1620, the other a mad dog (60$, on sale) that should have been a 3500, thats when we found out that mad dog was packaging 3520's in 3500 packaging, which they continued to do for a while.
Ok so I like rambling on, the moral of the story, they both bought 1620's from newegg with in a week of each other. Maxell002 worked perfectlly on one drive (I scanned them on my liteon and they were plenty good), the other drive actually failed to burn (I brought some of my own known good maxell002 to test in case it was a bad pack and they failed to even complete the burn). Firmware updates didn't help. It let them finish but the burns were really bad.
my opinion, the market for burners and media is so competitive, it has driven some out of the market, and with the big companies, do you think they check every few hundred drives for quality control, or every few hundred thousand (after all, we buy the 40$ drives, not the 140$ drives, right)? I think that even if your drives were made on the same day, the first drive and the last drive of the day may vary on specs (not nessasarily quality, but tolerances and or solder contacts that might cause variable conductivity, and of course there are endless mechanical aspects of the drive that might vary. They are all good drives, and they all work (from the good companies), but with the volume of drives they produce and at the cost they produce them, its no shock they vary, sometimes quite a bit.
I have said it (and I'm sure everyone is tired of it), and I'll say it again. There is no pefect drive/firmware/media combination. Find what works good on your drive and use it. Fyi ty is the best, verbatium is second, but it is very possible that they will not perform well on your drive. Its not liklly, but it is defanatlly possible. Find what your driven likes (and keeep in mind, firmware changes or if you don't mind voiding your warranty, firmware modifications can way fix things, there are bad firmwares), but again, find what your drive likes and use it!!!!!! Do not expect two drives of the same model and firmware to like th same thing!!!
And now I digress and say, this is just my opionion of the top of my head and I may be wrong in several respects, it's just an opinion, take it for that and alternative opinions are actually encouraged!!!!!

Thats not nessasarilly true. Drives that tend to be good, tend to bee good. I don't care what drive you buy, you are going to have to find media that your drive likes. You can spend any amount of money (under 200$ not profesional recorders that cost thousands), and there is no guarentee that it will like a particular media. IF you buy a good drive though, odds are high, you will be able to find several high quality medias that will reliablly burn exelent on your drive!!!! That is something that I promise because it is true. You may have a second bad drie, but you picked a good company, and odds are against it (thats based on sale drives, unfortunatlly I have no Idea what they send for waranty replacment, but if its not good, post and warn us.....

Can't see how the drive is able to like or dislike media...

Simply; with high quality media the chances are higher you'll get better results then on low quality media, on any DVDRW drive.
No need to pretend "the drive" has any feelings about the media.

And with BenQ 1640's SolidBurn technology you can get acceptable results even on low quality media, compared to other "common" DVDRW burners.

First of all, i don´t want to give the impression im completely unhappy with my new drive (if i was i would return it again), it actually burns well, it reaches good quality scores (about 95) and so far (a very short period of time indeed) all recorded DVDs showed no evident problem, it´s just that comparing with my previous drive and looking at both quality graphics, the differences are very evident, a lot more pifs (so far all under 8 though) higher pies and higher jitters while the first drive burned with just a few pifs and lower errors and jitter with the same media, it just amazed me and i just wanted to know the precise cause of these differences (more exactly used DVDs or drive) that´s all, i think the answer would be as you said there´s no perfect combination and i will have to try it a bit more, but anyway it was more a curiosity of mine than a real problem since i think all are acceptable burns after all

I absolutlly agree with your statment that with high quality media, your chances are much beter to get a good burn, and low quality media tends to perform just that way, low quality. I'm not farmiliar with benq solid burn technoligy but having just bought a rebadged 1640, I'm excited to learn about it. My point about how a drive feels about a media may have been mistated. I just meant to imply that you can get the best drive, the recomended firmware, and the best media, and there is no guarentee that it will burn good (it will for most but not everyone). All you have to do is go to the media forum and look at some of the burns from your favorite media (mine is ricohjpnr01, but look at ty or verbatium medias if you like). The simple fact is, you can have a good burner, a firmware that works for others on the same drive with the same media, and still get a bad burn. There is no guearentee that a drive/firmware/meida combination that works for one, or even for most, will work for everyone, in fact, it does not. As far as solid burn, I look foward to trying it out.
I'll also tell you this, I think my nec 3500 is the best dvd burner made. It burns everythingdvd exelent. It burns all medias, even crap ones decent (at least readabel and pi under 80 even with total crap media). I have seen 3500's burn poorly with media that burns great for me though (with the same firmware). Its not that great of a reader either. I would die if my 3500 ever failed, becaue it is such a great burner for me, but I know for a fact that medias that work exelent on my 3500, work poorly on other 3500's. there are variations in the best drives (fyi I know benq are among them short of the dq60), and do not mean to insult them at all (otherwise I wouldn't have been so excited to get a benq to play with).
In short though, just because a media works well for me or you doesn't mean it will work well for someone eles. Thats why it is so great that we have all these testing tools. I'll say it again, find the media that works well with your drive and stick with it. there is no perfect media that works well for all though (even ty or verbatium burns bad on good drives sometimes).

I fully understand. Also, nero quality scores are very subjective. A perfect burn with some little anomoly that would never effect palyback can kill your score. I personally am pretty anal about how my disks scan, but then again I usally just run a kprobe test and maybe a transfer rate, and if I scanned further, I might find faults in my so called good burns. Lets face it, anything over 90 is going to play just fine. (I dont do cdspeed scans (I do kprobe), but the same princaple applys. I get pissed if I get above a certain point, but in rteality, you can go way beyond that point and still have a very good burn. Personally I think any pi spike above 20 is sign of a low quality burn, because the media I use is well matched to the drives I use and I can do that, but in reality, the book spec is 280 pi and I am just being over critical. You are too. a disk that scores 90 plays fine, but hey, why not shoot for perfection, I do!!!!