The final part of a series of postings about the BenQ DW1640 DVD±RW drive looks at some of its other special features and explains why I’m so fond of this particular drive.

**Quality Testing**

When users burn recordable discs, they don’t have a ready way to gauge the quality of the recording. Owing to the presence of error correction data within the recorded data, a simple read-back verify would succeed as long as sufficient data remained readable to recover the original data post-error-correction. A user would not have any means to more accurately determine whether a disc was “close” to being unrecoverable or not, possibly save for a transfer-rate test where speed dips were indicative of drive retries although the cause would not be clearly understood (e.g. could be disc warpage).

To that end, normally such information can only be garnered through the use of expensive disc analyzers such as CATS. However, this ability began cropping up on drives as part of less-well-documented firmware features that exist with drives of specific chipsets. The most famous are the Mediatek-based drives from LiteOn, where Karr Wang helped popularize media scanning with his KProbe2 tool, which later on, was followed up by DVDScan which has since been abandoned. It was then discovered that other drives with other chipsets also had this ability to differing degrees, including the BenQ DW1640.

To do such quality scans requires third-party software. The ones I use most are Nero CD-DVD Speed and Opti Drive Control, both by Erik Deppe, however there is at least one other alternative (that I will not name owing to some political issues).

The drive supports scanning both CD and DVDs. In the below set of four images, I scanned four different types of blank CD-R (one of the Plasmon discs is a mis-identified Ritek) recorded by a slimline DVD recorder at 24x. Most slimline drives are terrible, but this LiteOn DS8A8SH seems to be somewhat passable.

The drive can return the C1/C2 error count simultaneously with jitter. Lite-On drives can do the same, although jitter support varies and typically is done “post-test” in a second pass. Applicable limits are generally a C1 maximum below 220 (as that is the “failure point”) and preferably no C2 errors. This has been met for all discs. Jitter should be as low as possible, generally below 10-12% is a good idea.

The drive can also test DVDs, returning the PIE, PIF and POF counts with jitter. The drive reports PIFs as sum8 values rather than the standard sum1. As a result, direct comparison with Lite-On drives and ECMA standards for PIFs is a bit difficult. PIEs should be below 280 (limit to failure), and PIFs should be below 4 (sum1) or about 16 (sum8). Note that the PIFs for sum8 condition is not 8 times the sum1 condition, as statistically, there could be a chance that the PIFs are “bunched” in one block which would result in an actual read error. There should be no POFs, else unreadable data is quite likely. Jitter should be below 12%.

With this information, it’s possible to get an idea of what the drive is seeing when it tries to read the disc, although the absolute figures are probably unreliable and incomparable when comparing across different models of drive.

There were other drives, including some combo drives and readers which had scanning ability. However, many of them were not particularly reliable, partly owing to their mostly CAV characteristics, which show increased error rates towards the outside edge not due to recording issues but possibly mechanical ones. CLV scanning is generally preferred, especially at 4x for DVDs, as this reduces the “mechanical” contribution to the variance in scan results.

**99-minute Overburning Support**

When CD-R/CD-RW media enjoyed a price advantage over DVD media, the quest for ever more capacity was constant, and special blank media of 90 minutes and 99 minutes were released for a limited time. These pushed the standards somewhat in regards to the pitch of the groove, allowing more data to squeeze into the same radius. These discs were all identified as “standard” 79m59m74f style 80 minute blanks, and **required overburning** to achieve their full capacity. Not all drives were capable of handling this properly, and while the 90 minute blanks were generally quite compatible, the 99 minute ones almost **always** caused problems.

As it turns out, I still have a few 99 minute discs left, so it was a good thing as I can demonstrate the BenQ’s abilities.

On a simulated overburn, the BenQ DW1640 was able to register a maximum capacity of 99 minutes 56 seconds and 41 frames. Such long simulated capacities are nice, but can it actually be achieved?

I decided to write a 99 minute 00 second 00 frame disc, as in my experience, getting too close to the simulated value will cause issues. Another frequent cause of issues is the **lead-in of the disc **uses the same addresses as used by the recorded data.

Once burned, the disc achieved a practically flawless read-out on the BenQ DW1640 as well as a LiteOn DH16A6L, LiteOn iHBS212, LG BH16NS55 and LG GGW-H20L. It was an unexpected result, as contemporary drives in that era would often have problems maintaining high read speeds as they struggled to cope with the marginal disc that was just out of spec.

A quality test showed the disc wasn’t in any danger of breaching the C1 limit, and registered zero C2 errors although the jitter was high, possibly due to the fact the manufacturer of the disc is unknown and the write strategy possibly less than optimal. But that’s still better than **not being able to burn the disc at all.**

If you compare this with other drives, one of several results can occur. Some drives simulate and “pretend” they can record forever, such as this LiteOn DH16A6L –

Others will honestly bail out, but short of the full capacity of the disc, such as the result from my LG GGW-H20L –

But when it comes to writing, all bets are off, as the actual result may not even work as drives struggle to finalize the disc or fail to maintain tracking towards the outer area. The BenQ, however, has always been a reliable writer of these types of marginal discs **and has been quite a good reader as well in handling such odd media**. It does go without saying that in this case, being able to overburn this much also means handling overburning of regular 80 minute CD-Rs quite well.

**DVD+R Overburning Support**

While CD-R overburning was easily achieved using contemporary burning software of the time (Nero) and generally just worked, DVD overburning was completely different. In fact, I wasn’t even convinced that DVD overburning could happen and made this post on 14th October 2005 stating my opinion which was quickly refuted as being real, but only for Plextor users.

Attempting to overburn on most drives with DVD+R media results in a burn right up to the limit before suddenly bailing out resulting in a “truncated” burn. However, simulating such a burn on the BenQ DW1640 resulted in a true simulation (no burn to disc) and a value which suggested overburning **was** indeed possible.

I was intrigued by it, hence my posting about it. Needless to say, I was soon steered into this post by Erik Deppe (the man behind this exact software I’m using to test the discs) which claimed back in 22nd August 2005 that he managed an overburn but a severe quality issue occurred. There wasn’t much action after this **until I came along** the day after I posted my disbelief in overburning DVDs and realized the issue as being the Solid Burn outer calibration track. Disabling Solid Burn through QSuite allowed me to burn my first overburnt disc (and presumably the **world’s first without the quality issue**) with the BenQ DW1640 cross-flashed to EW164B. As a result, I also beta-tested ImgBurn version 1.0.0.8 with overburn support for DW1640. It wasn’t a complete success, as overburns had to be greater than about 4500MB or else the drive fails to finalize, but it did allow us to create **strangely non-standard discs** many years prior to the advent of BurnerMAX for Mediatek based drives and DVD+R DL media.

The DVD+R overburn was successful.

Readback on the DW1640 did show some slow-downs towards the end, but that may also be because the data rate exceeds the chipset’s nominal specifications.

The disc quality is not too bad according to the DW1640 – a bit poor on the inside ring, but otherwise quite decent.

Testing it with two LiteOn drives shows the DH16A6L felt the burn quality to be poorer but not unreadably so. The newer LiteOn iHBS212 Blu-ray drive instead sees the burn as horrible, but that is because it doesn’t seem to scan *properly* anymore, disobeying the speed request for 4x and not scanning at CLV which puts additional stress on the disc.

Surprisingly, trying to read back the overburnt disc in the LiteOn DH16A6L (at maximum and restricted to 8x), LiteOn iHBS212, LG BH16NS55 and LG GGW-H20L all **failed to read to the end, most bailing out at the “normal” limit size of a regular DVD**. Might this be a firmware bug related to the way the drives support dual-layer discs? I don’t know for sure. But what I do know is that the **data is there**, and the laser pick-up can reach it (as the quality scans show). But **the other drives can’t read it**. It’s always fun to create such *strangely incompatible discs*.

In case you were wondering, overburning DVD-R has not been a possibility. Using the Nero CD-DVD Speed software, a simulation of DVD-R overburning is possible with the DW1640.

However, when attempting to burn, we find that burns proceed to writing all the data and then fail. Worse still, the drive also ignores our request for 4x write speed.

Ejecting and re-inserting the disc results in a “blank” disc appearing, as none of the inner metadata has been properly written. The data area of the disc has been burned, and the disc is thus a coaster.

Giving it a go with the latest Opti Drive Control software results in a similar result – it just doesn’t finish and a coaster which appears blank is the end result.

Imgburn, being the ever-so-honest software, asks the burner to reserve a track of a size greater than allowed up-front pre-burn, and the burner denies this request thus making overburning impossible through this route. It’s good to rediscover that nothing has changed since 2005.

**Firmware Modification**

Thanks to the work of ala42 on MediaCodeSpeedEdit tool (MCSE), it is possible to read the firmware’s media support list, rename/reassign strategies to change write speeds or quality and patch the rip-lock to speed up DVD-video ripping.

This basically bought “Omnipatcher” abilities that were bought to LiteOn based drives by the codeguys to a number of other drives. As someone who also owned LiteOn drives at the time, it was nice to see “feature parity”.

In fact, I did help out with some testing of LG GSA-4163B patches back in 2005, as can be seen in the changelog.

1.0.5.9 25 Aug 2005 Thanks to Crisao23, ise, lui_gough, PumaUK for testing the LG patches [...] - changed GSA-4163 support overspeeding of 4x -R media does not work supports overspeeding of 4x/8x +R media to 12x and 16x supports overspeeding of 8x -R media to 16x all +R MIDs already supporting 12x can be used @16x six additional +R MIDs can be swapped to 12x/16x six additional -R MIDs can be swapped to 16x

**Conclusion**

Considering the BenQ DW1640 wasn’t particularly expensive compared to its contemporaries, it was actually quite a good drive for an average user as it delivered on good robust disc reading, quality disc writing at higher speeds and extra features to allow one to tinker with the drive and assess the quality of discs. The added firmware modification support is a big bonus as well.

On the downside, it didn’t support as many media types as some of the competing models, and it had no support for DVD-RAM (for which I kept an LG GSA-4163B for at the time) or Mt. Rainier (which I had an LG GCE-8523B as well). The quality scan features reported PIFs as sum8-values rather than sum1, thus could not be directly compared with the LiteOn or ECMA standard guidelines, although different drives did always vary with their opinions of the quality of discs.

It kept me good company as my primary burner for many years, and I still enjoy having it around for the “odd job”. I suppose this write-up is my way of thanking the drive for years of trouble-free service. That being said, most modern burners won’t have many of these features exposed to the users, but their burn quality at high speeds has definitely improved along with media support.

It’s right around now that I wished I was the owner of a Plextor drive for some GigaRec fun. It’s yet another way to get more data onto a CD-R, and one which can produce strange compatibility issues too.

**Appendix: BenQ DW1640 Media Code Support List for Firmware Version BSRB via MCSE**

Media Code Speed Edit V 1.2.0.10 ------------------------------------------ Firmware: BENQ DVD DD DW1640 BSRB Bootcode: ------------------------------------------ Overall supported media types: 253 ------------------------------------------ DVD+R9 supported media types: 22 DVD+R supported media types: 95 DVD+RW supported media types: 17 DVD-R9 supported media types: 3 DVD-R supported media types: 78 DVD-RW supported media types: 38 ------------------------------------------ DVD+R9 supported media types: 22 ------------------------------------------ CMC MAG D01-000 2.4x CMC MAG D02-000 8x,6x,4x,2.4x CMC MAG D03-064 8x,6x,4x,2.4x CMC MAG D04-000 8x,6x,4x,2.4x INFOME D01-000 2.4x MBIPG101 R10-065 8x,6x,4x,2.4x MKM 001-000 8x,6x,4x,2.4x MKM 001-000 8x,6x,4x,2.4x MKM 003-000 8x,6x,4x,2.4x PHILIPS CD2-000 2.4x PHILIPS PD2-000 2.4x PRODISC D01-000 2.4x RICOHJPN D00-001 2.4x RICOHJPN D01-001 2.4x RICOHJPN D01-002 8x,6x,4x,2.4x RICOHJPN D01-067 8x,6x,4x,2.4x RITEK D01-001 2.4x RITEK D03-001 8x,6x,4x,2.4x RITEK D03-130 8x,6x,4x,2.4x RITEK S04-001 8x,6x,4x,2.4x RITEK S04-066 8x,6x,4x,2.4x RITEK X01-001 2.4x DVD+R supported media types: 95 ------------------------------------------ 4MSYSP I08-000 8x,4x AML 002-000 8x,4x AML 003-000 16x,12x,8x,4x BeAll000 P80-000 8x,4x BeAll000 PG0-000 16x,12x,8x,4x CMC MAG E01-000 8x,4x CMC MAG M01-000 16x,12x,8x,4x DAXON AZ2-000 8x,4x DAXON AZ3-000 16x,12x,8x,4x DAXON CY3-000 16x,12x,8x,4x DDDessau V30-000 8x,4x DIGVAL R01-000 12x,8x,4x DT-D03 004-000 8x,4x Dvsn+160 001-000 16x,12x,8x,4x EMDP 000-000 8x,4x EMDPAZ01 000-000 16x,12x,8x,4x FTI 016-000 16x,12x,8x,4x GSC503 H01-000 8x,4x GSC503 H01-000 8x,4x GSC503 H02-000 16x,12x,8x,4x IMC JPN R01-000 8x,4x INFODISC R20-000 8x,4x INFOME R20-000 8x,4x INFOME R30-000 16x,12x,8x,4x IS01 002-000 8x,4x IS02.... 001-000 8x,4x ISSM 001-000 8x,4x ISSM 003-000 16x,12x,8x,4x LD M04-000 16x,12x,8x,4x LD S03-000 8x,4x LD S04-000 16x,12x,8x,4x LGEP16 001-000 16x,12x,8x,4x LONGTEN 002-000 8x,4x MAM M02-000 8x,4x MAM M04-000 12x,8x,4x MAXELL 002-000 8x,4x MAXELL 003-000 16x,12x,8x,4x MBIPG101 R04-001 8x,4x MBIPG101 R05-001 16x,12x,8x,4x MCC 003-000 8x,4x MCC 004-000 16x,12x,8x,4x MICRON 001-000 8x,4x MJC 003-000 8x,4x MJC 005-000 16x,12x,8x,4x MPOMEDIA 080-000 8x,4x MUST 002-000 8x,4x MUST 006-002 16x,12x,8x,4x NAN YA FLX-000 16x,12x,8x,4x NANYA ALX-000 16x,12x,8x,4x NANYA CHX-000 8x,4x NANYA CLX-000 8x,4x NANYA RJB-000 NSD R40-000 12x,8x,4x OPTODISC F16-000 16x,12x,8x,4x OPTODISC OR8-000 8x,4x OPTODISC R16-000 16x,12x,8x,4x PHILIPS C08-000 8x,4x PHILIPS C16-000 16x,12x,8x,4x PHILIPS C16-001 16x,12x,8x,4x POS R01-000 8x,4x POS R05-000 16x,12x,8x,4x PRODISC R03-003 8x,4x PRODISC R04-004 16x,12x,8x,4x PRODISC R05-001 16x,12x,8x,4x Philips 081-000 8x,4x Plasmon1 C01-000 8x,4x Plasmon2 C01-000 16x,12x,8x,4x RICOHJPN R02-003 8x,4x RICOHJPN R03-004 16x,12x,8x,4x RITEK F16-001 16x,12x,8x,4x RITEK P16-000 16x,12x,8x,4x RITEK R03-001 8x,4x RITEK R03-002 8x,4x RITEK R04-001 16x,12x,8x,4x RITEK R05-001 16x,12x,8x,4x SAST A01-000 16x,12x,8x,4x SAST P01-000 8x,4x SKC P16-000 16x,12x,8x,4x SKC P80-000 8x,4x SKYMEDIA R03-000 8x,4x SONY D11-000 8x,4x SONY D21-000 16x,12x,8x,4x TDK 002-000 8x,4x TDK 003-000 16x,12x,8x,4x ULTRAN 202-000 8x,4x ULTRAN 212-000 16x,12x,8x,4x VANGUARD 001-000 8x,4x VDSPMSAB 002-001 8x,4x VDSPMSAB 004-001 16x,12x,8x,4x VIVA 002-000 8x,4x WFKA11 211-000 8x,4x WINGSHIN 001-049 8x,4x YUDEN000 T02-000 8x,4x YUDEN000 T03-000 16x,12x,8x,4x Yi Jhan 004-000 16x,12x,8x,4x DVD+RW supported media types: 17 ------------------------------------------ CMC MAG W01-000 2.4x CMC MAG W03-000 8x,6x DAXON W81-000 8x,6x INFODISC A01-002 2.4x INFOME A20-000 8x,6x MBIPG101 W03-000 2.4x MBIPG101 W05-000 8x,6x MCC A01-000 2.4x MKM A03-000 8x,6x OPTODISC OP8-000 8x,6x PHILIPS 010-001 2.4x PHILIPS RW8-000 8x,6x PRODISC W01-002 2.4x RICOHJPN W21-001 8x,6x RITEK 001-001 2.4x RITEK 008-000 8x,6x SONY S21-000 8x,6x DVD-R9 supported media types: 3 ------------------------------------------ CMC MAG. AD4 4x,2x MKM 01RD30 4x,2x RITEKP01 4x,2x DVD-R supported media types: 78 ------------------------------------------ 0000-TPC16A1 16x,12x,8x,4x BeAll G16001 16x,12x,8x,4x BeAll G80001 8x,4x CMC MAG. AE1 8x,4x CMC MAG. AM3 16x,12x,8x,4x CMC MAG. AM3 16x,12x,8x,4x DAXON008S 8x,4x DAXON016 16x,12x,8x,4x DAXON016S 16x,12x,8x,4x DAXON016S 16x,12x,8x,4x DKMZ01 8x,4x Dvsn-80 8x,4x FTI RG16 16x,12x,8x,4x FUJIFILM03 8x,4x FUJIFILM04 16x,12x,8x,4x GSC003 8x,4x GSC004 8x,4x GSC005 16x,12x,8x,4x IMC JPN R01 8x,4x INFODISC-R20 8x,4x INFOMEDIAR20 8x,4x ISSM R01 8x,4x KDTVVV 8x,4x LEADDATA S03 8x,4x LEADDATA S04 16x,12x,8x,4x LGE08 8x,4x LGE16 16x,12x,8x,4x LONGTEN 003 8x,4x MAM8XG01 8x,4x MBI 01RG40 16x,12x,8x,4x MBI 01RG40 16x,12x,8x,4x MBI 03RG30 8x,4x MBI 03RG40 16x,12x,8x,4x MBI03RG30 8x,4x MCC 02RG20 8x,4x MCC 03RG20 16x,12x,8x,4x MJC M005 16x,12x,8x,4x MJC ME 8x,4x MUST 003 8x,4x MUST 007 16x,12x,8x,4x MXL RG03 8x,4x MXL RG04 16x,12x,8x,4x NAN YA A01 8x,4x NAN YA F02 16x,12x,8x,4x NSDR40 8x,4x OPTODISCR008 8x,4x OPTODISCR016 16x,12x,8x,4x POMS3A 8x,4x POMSI002 8x,4x POSG06 8x,4x POSG08 12x,8x,4x PRINCO8X02 8x,4x Plasmon1A 8x,4x Plasmon2A 8x,4x ProdiscF01 8x,4x ProdiscF02 16x,12x,8x,4x ProdiscS04 8x,4x ProdiscS05 16x,12x,8x,4x RITEKF1 16x,12x,8x,4x RITEKG05 8x,4x RITEKG06 8x,4x RITEKM16 16x,12x,8x,4x SAST100 8x,4x SKC M801 8x,4x SONY08D1 16x,12x,8x,4x SONY16D1 16x,12x,8x,4x TAROKO-MX8 8x,4x TTG02 8x,4x TTH01 8x,4x TTH02 16x,12x,8x,4x TYG02 8x,4x TYG03 16x,12x,8x,4x ULTRAN102 8x,4x UME01 8x,4x UME02 12x,8x,4x VANGUARD01 8x,4x WINGSHING08 8x,4x Yi Jhan 003 8x,4x DVD-RW supported media types: 38 ------------------------------------------ CMCW02 2x CMCW03 4x,2x CMCW04 4x CMCW04 6x DAXON_RW2X01 2x INFOMEDIA 2x JVC/VictorT7 1x JVC0VictorD7 4x,2x JVC1Victord7 4x JVC1Victord7 6x JVC_VictorW7 2x MBI01RWG 20 4x,2x MCC 00RW11N9 1x MCC 01RW11n9 2x MCC 01RW4X 4x,2x MKM 01RW6X01 4x MKM 01RW6X01 6x OPTODISCK001 1x OPTODISCW002 2x OPTODISCW004 4x,2x OPTODISCW006 6x PRINCO 1x PRINCO 2x PRINCORW0004 4x,2x PRINCORW2X01 2x Prodisc DW04 2x Prodisc DW06 4x,2x ProdiscDVDRW 1x RITEK000V11A 1x RITEKW01 2x RITEKW04 4x,2x RITEKW06 4x RITEKW06 6x SONY000000U9 1x TDK502sakuM3 2x TDK601saku 4x,2x TDK701saku 4x TDK701saku 6x

Well, I bought 12 assorted DVD burners from eBay recently, and…. 5 of them are this model, the DW1640. I’ve been playing with QSuite using them some, and it’s kind of interesting that these drives support TE/FE scans on DVD only while the various PLDS drives I’ve used (iHASx24 series revisions A and B) seem to support it on CD only.

Also of note is that it is possible to “decode” the errors given by Opti Drive Control. The first and second digits are the sense key (not important), the third and fourth are the ASC, and the fifth and sixth are the ASCQ. You can look up the ASC and ASCQ here to get a text description of the error: http://www.t10.org/lists/asc-num.txt

For example, if we take the error message given above of “error, code 052102”, this gives the following:

Sense key (not important): 0x5

ASC: 0x21

ASCQ: 0x02

Looking at the above list, the appropriate line is this one:

“21h/02h R INVALID ADDRESS FOR WRITE”

If you feel like looking up the sense key as well, there is a list of them here: http://www.t10.org/lists/2sensekey.htm

0x5 means “ILLEGAL REQUEST”.