Observations on optical disc drives

General

Rotation speeds

Results of various acoustically measured angular speeds by matching tone pitch with sine wave tone generator (Android app “com.dutchmatic.patone”), divided by 2 or 4 depending on octave, multiplied by 60 to get rotations per minute (rpm), and mathematically verified by measuring other CAV and CLV (÷2.4 at inner edge) rotation speeds.

• CD 48×CAV: 9720 rpm
• DVD single layer 16×CAV: 9360 rpm
• DVD dual layer 12×CAV: 7680 rpm
• BluRay dual layer 12×CAV: 10000 rpm

Speed limits

• Most half-height (desktop) DVD writers released since 2007 have a speed limit of 16×CAV for DVD±R single layer and 12×CAV for DVD±R dual layer, DVD-ROM dual layer and DVD±RW.
• Many dedicated DVD drives released between 2005 and 2010 supported writing CD-RW UltraSpeed + (32×Z-CLV), DVD-RAM at 12×P-CAV, DVD+R DL at 16×CAV, DVD-R DL at 12×CAV and DVD±R at speeds beyond 16×CAV, while more recent backwards-compatible Blu-Ray drives have limits of CD-RW UltraSpeed (24×Z-CLV), DVD-RAM 5×CLV, DVD±R DL 8×CAV and DVD±R 16×CAV writing speeds.
• DVD-ROM drives appear to have faster disc recognition times, possibly due to having to differentiate between fewer media types (only by coarse disc type and reflectivity, no sub-types and whether the disc is empty or written to)
• DVD-ROM drives appear to have faster random read access times, possibly because of the lighter optical pickup unit that houses the laser lens.

Disc damage

• Some damaged discs happen to be better readable at lower speeds (generally factory-stamped media), while others actually at higher speeds (generally recordable media). The reason for this behaviour is unknown.
  • A possible explanation is that disc damage could distract the tracking of the lens too much sideways at lower speeds, while at higher speeds, the lens is not able to dodge the track sideways fast enough to lose track of it.
  • Higher rotation speeds and lower laser power might improve digital audio extraction (DAE) readability by reducing the likelihood of the optical drive getting hiccup-stuck.
• Some DVD writers falsely detect a too heavily scratched DVD-RW as empty.
• Physically undamaged factory-pressed discs could still have reading issues at higher angular and/or linear velocities.
• New LG BluRay drives tend to perform poorly with damaged audio CDs (tends to get hiccup-stuck at lower speeds), while TSSTcorp drives released between 2006 and 2010 handle damage well.
  • Optical drives tend to perform better DAE's on damaged CD-R than normal CDs. Is it possible that some optical drives use too much laser power for reading normal CDs, which negatively affects handling of scratches?
• Rewriting a CD-RW from the brand SK multiple times without first blanking it occasionally leads to logical C2 errors in the thousands, which can be repaired by fully blanking the CD.
  • Drives from LiteON and HL-DT-ST try to deliever a clean digital audio extraction (DAE), thus refuse to return data from such an audio CD, while drives by TSSTcorp tend to prioritize speed during DAE and just read through it and return the noisy audio.

Packet writing

• When using a UDF live file system on an optical drive of which the writing speed is higher than the reading speed (packet writing software usually requests the highest possible writing speed), and software (including the packet writing software itself) read-accesses the disc, the disc will spin down to the throttled reading speed just to read the requested sector, which causes it to repeatedly inefficiently and annoyingly spin up for writing and down for reading.
  • This problem could be solved if optical drives allowed power users to optionally manually enforce reading and writing speed ranges.
  • CLV (constant angular velocity) mode during random writes could significantly slow down the writing process, which especially is a problem when adding many small files.
    • A possible solution would be the ability for the user to enforce CAV (or at least P-CAV) mode. Evidently, rewriteable media is able to tolerate deviations from the rating speeds by a factor of 2.4× from the lowest to the highest technically supported linear writing velocity.
• When treating a DVD+RW like an USB flash drive and writing to it from many different optical drives, many beautiful rings can be seen on the data side that add up over time.

Weardown

The laser light of earlier optical drives tends to lose power after recording too many discs. Possible effects include:

• A DVD recorder used to recorded onto many DVD-RW's might not be able to detect CD-RW at all (as if no disc were inserted in the tray).
• However, reading DVD-RW with an aged DVD laser surprisingly works more reliable than DVD-R.
• PRINCORGM1 media appears to have a higher reflectivity than other DVD-R media, making it more detectable with drives that have an aged DVD laser.
• DVD+R appears to be more reliably readable than DVD-R with an aged DVD laser.
• Moisturizing the disc by breathing against it imminently before closing the tray could make DVD-R more detectable because the drive assumes a higher laser power to begin with due to the temporarily lower reflectivity caused by the temporary fog on the disc's data layer.
  • In rare occasions, this might lead to the detection of the wring disc type (e.g. DVD-RAM)
• In rare occasions, a drive with aged laser might detect a normal DVD-R (12cm diameter) as a miniature (8cm diameter) DVD-R.
• DVD-R appears to be more detectable with an aged laser if the drive was warmer upon insertion.
  • The possible reason for that is that the higher ohmic resistance caused by the warmth makes the drive compensate by using a slightly higher voltage for the laser.

Error scanning

Observations on error/quality scanning. The list is currently far from complete.

• Nero DiscSpeed disables error scanning on discs where the last session is not closed.
• Although it is possible to record rewriteable media at underspeed, the more the recording speed deviates from the rated speed, the higher is the error rates.
  • When recording high-speed media (e.g. 6× speed DVD-RW) on a slower drive (e.g. slim type drive), it has to record 6× zoned constant linear velocity (Z-CLV), of which the zones have speeds of 3× CLV, 4× CLV and 6× CLV.
    According to tests, the error rate is around 1.4K PIE and 100 PIF in the 3× CLV zone but only around 600 PIE and 20 PIF in the 4× CLV zone, and only 80 PIE and 3 PIF in the 6× CLV zone.

Specific media

• CD-RW HS media by the vendor SK appears to be more readable than those by the vendor Verbatim on early CD players which struggle with low media reflectivity.
• An audio track to a CD-RW can be appended without rewriting the entire disc, by unclosing the session and adding the track in TAO (Track-at-once) mode.
  • Example command – adapt if necessary: wodim blank=unclose dev=/dev/sr2 -tao -v -audio AudioFile.wav

Software

• On internal SATA and PATA/IDE drives (both half-height and slim type) used externally through an adapter, starting the RimhillEX software for controlling disc speeds iniates a full blanking command on CD-RW and DVD-RW if inserted (but not DVD+RW or any other disc type). The optical drive becomes and stays unresponsive until disconnected.
  • This only happens when starting the software while the disc is inserted, not if the software was has already been opened before insertion.
  • On external drives (both half-height and slim type), the drive spins up upon starting RimhillEX, and the LED indicator blinks in a way that indicates writing access, but shortly after spinning up, it spins back down instead of performing a full blanking and becomes responsive again.
• When performing a test burn using Nero DiscSpeed, it writes the speed graph data and drive model type to the end (outermost edge) of a disc (latter readable using HEX editor), which can be viewed with the software.
  • This is not to be confused with the DVD-R/RW recorder information (model of used drive), which is written by most, if not all DVD-R/RW writers at the beginning (innermost data area edge) of the disc and can also be viewed inside Nero DiscSpeed.

Vendor-specific

Observations with optical drives of specific vendors.

TSSTcorp

• ✅ TSSTcorp drives support error scanning (C1, C2, PIE, PIF).
• After encountering disc damage, TSSTcorp drives allow speeding up to full drive speed on later undamaged parts of the same disc, while HL-DT-ST drives limit the speed after encountering disc damage until ejected and reloaded.
• Upon ejection (both ejection button and SCSI command) while the disc is not moving, the drive often does unnecessarily spin up (to 10×CAV for CD and 4×CAV for DVD), then spin down again and eject, instead of ejecting immediately.
• VCD (VideoCD) reading speed is limited to 16×CAV, for both slim type and desktop (half-height) drives.
  • HL-DT-ST doesn't mind reading VCDs at full speed (48×CAV (constant angular velocity) and even 52×CAV for few drives like GDR-H20N)
• While having a good recording quality on CD-RW HS media by Verbatim, TSSTcorp drives appear to struggle with CD-RW HS media by the vendor SK.
• Unlike HL-DT-ST drives, TSSTcorp optical drives tend to read through damaged audio CDs
  • This includes reading through logical (repairable non-physical) errors on a CD-RW by vendor “SK”, caused by rewriting it too many consecutive times (>10) without full blanking (on any drive), leading to logical error rates of >3000 C2 errors, where the audio is barely hearable in the noise.
  • In comparison, LiteON and HL-DT-ST optical drives are likelier to return a CDDA sector as errornous instead of returning the damaged data.
• When trying to close the tray via SCSI command on a laptop (slim type) drive, it returns the SCSI code 02 / 3A / 02 (“MEDIUM NOT PRESENT - TRAY OPEN”), unlike optical drives by HL-DT-ST.
• On load or eject command for half-height drives, the drive only responds after the loading/ejection is finished, while HL-DT-ST drives respond immediately, allowing to respond to further commands before the tray has finished ejecting/closing.
• When an internal PATA/IDE drive is used externally through an adapter, disconnecting the USB plug from the port powers off the entire drive, while a HL-DT-ST PATA/IDE drive keeps running (temporary idle spinning; tray can be ejected and closed), although restarting on reconnection.
  • If the PATA/IDE data interface is disconnected, but not the power interface, the TSST drive powers on again. The state above only applies if the USB is disconnected while the PATA/IDE data interface unit is connected.
  • This is not the case with internal SATA drives connected through an external USB adapter.
• For audio CDs, some TSSTcorp optical drives do not respond to eject /dev/sr[number] -x [number] or hdparm -E [number] /dev/sr[number], but when played back using mplayer -cdrom-device /dev/sr[number] cdda:// [parameters], they slow down to 10×CAV while speeding up to 40×CAV when read through cdparanoia.
• SH-S182 (2006, half-height): Writes Verbatim CD-RW HS media properly, but SK CD-RW HS media still appears blank after writing. Apparently, it miscalibrates the laser and uses too little power.
  • Allows writing speeds of 4×CLV and 10×CLV for CD-RW HS media.
  • Excellent DAE (digital audio extraction) performance on damaged audio CDs: Low noise, no skipping except when reading thicker scratches at lower speeds.
• Earlier TSSTcorp drive models (until ~2007) write the last few sectors (independently from used disc capacity) on CD-R media improperly, which could cause the end of the last written file (with the highest LBA (logical block address)) to be unreadable.
  • Some disc authoring/writing software has an option named “Pad data tracks”, that appends a few additional blank sectors at the end of the data stream to prevent this problem.
• SE-208DB, SN-208FB(but not SU-208CB) (2012, slim-type): Uses an inferior ejection mechanism, where the optical pickup unit (that houses the laser lens) pushes against the edge to open the tray. For this, it needs to move all the way to the end, creating a delay on ejection and a sound from the laser moving to the end.
  • In return, the SE-208DB and SN-208FB have an excellent reading performance on a heavily scratched audio CD, while the SU-208CB is not much better than the BE14NU40.
  • The damaged DVD reading performance of all three models is similarly good.
  • The BLDC motor of the SE-208DB and SN-208FB sound alike, while the SU-208CB sounds somewhat different.
  • SE-208/SN-208 appear to have a better DVD±R recording quality than SU-208, both similar on CD-R.
  • SU-208 appears to have a better recording quality on CD-RW than SE/SN-208
  • The SE-208/SN-208 have a vibration detection that limits speeds to the lowest values of 10×CAV for CDs and 4×CAV for DVD. However, that vibration detection is rather sensitive and occasionally unnecessarily limits the disc speed.
• TS-H653B (2007, half-height)
  • According to a user report, this model has compatibility issues with a specific SATA adapter. This issue may exist in several other optical drive models as well,.

HL-DT-ST

• ❌ HL-DT-ST drives lack one of the greatest benefits of optical media: Ability to run quality scans.
  • Some drives (e.g. BE12LU38, BE14NU40, /BE16NU40) support C2 error scanning only, but unreasonably halt scanning at the first CU error.
• More recent HL-DT-ST drives such as the BU20 do not halt the disc upon reaching the idle spinning time-out (usually 30 seconds to 1 minute), but just let it spin out.
• Speed throttling due to disc damage does disable the automatically dismissed speed options, even for undamaged parts of the disc, until the next ejection. This means that software such as RimhillEX or commands such as eject /dev/sr_ -x [speed] can no longer call for these higher speed options until ejecting and re-loading the disc.
• The writing speed options on more recent HL-DT-ST desktop drives are more narrow, possibly to maximize the recording quality. Examples:
  • On 16× rated DVD±R media, the only available speed options are 16×CAV, 12×P-CAV and 8×P-CAV, while TSSTcorp DVD writers offer speed options starting at 2×CLV.
  • The only available speed options on 4× and 6× rated DVD-RW media is the same respectively, while drives by other vendors offer the speed options 2×CLV, 3×CLV, 4×CLV and 6×CLV (Z-CLV on earlier models), of which the highest option is the rated speed of the DVD-RW media.
• Connecting the USB port of a powered-on half-height external HL-DT-ST drive to any power source such as a power bank (untested with drives of other vendors) does close the tray.
• GDR8162B (2003, half-height ROM) (PATA/IDE via external adapter):
  • When breathing against a CD-ROM/R immediately before insertion, the lower reflectivity caused by the temporary fog causes the drive to detect it as CD-RW, which suggests that many earlier CD/DVD-ROM drives distinguished between factory-pressed (CD-ROM)/write-once (CD-R) and rewriteable (CD-RW) media by measuring the reflectivity.
  • Issuing a disc speed command changes the angular spinning speed immediately without needing to read any data.
  • For CDs, the only manually requestable speeds are 24×CAV, 32×CAV, 40×CAV and 48×CAV (availability varies per disc type and integrity). However, on damaged media, the drive might limit the speed to 10×CAV or 4×CLV, which can not be manually requested.
    • Damage can be simulated by confusing the drive using the command rpt=10;while [ $rpt -gt 0 ]; do cdplay 1 start -d /dev/sr[number];cdplay 2 start -d /dev/sr[number]; rpt=$(( rpt - 1 )); done, forcing the speed down to 10×CAV or even 4×CLV. This requires a disc with ≥2 audio tracks. This command might only work on somewhat damaged CDs. You may adapt the track numbers to set it to access more damaged parts of the disc.
  • Requesting the playback of VideoCD (vcd) contents from an audio CD (cdda) using mplayer -cdrom-device /dev/[name of SCSI ROM] vcd://[track number] -cache [kB] -cache-min [percemt]] causes the drive to disconnect and require physically being reconnected.
  • Appears to struggle reading CMC Magnetics DVD-RW media, presumably due to low reflectivity, but manages to read RITEK DVD-RW and DVD+RW just fine (at nonstandard 5×CAV speed)
  • Other reading speeds: DVD-ROM DL: 8×CAV, DVD±R: 6×CAV, CD-RW: 40×CAV, VCD (CD-ROM/R/RW): 40×CAV.
• GDR-H20N (2007, half-height ROM) (SATA via external adapter):
  • Supports DAE (digital audio extraction) of CD and CD-R at 52×CAV, while most optical drives throttle it at 40×CAV.
  • Supports reading factory-printed CD and CD-R with VideoCD contents at 52× CAV too.
  • Operates well on half the supposed voltage (6 volts), albeit at a lower spinning speed.
• More recent models limit DVD-Video and DVD-Video DL reading speed to 12×CAV and 8×CAV respectively, rather than 16×CAV and 12×CAV respectively.
• More recent models may return bad (damaged) sectors (blocks) on video DVDs, possibly to smooth out playback but with the risk of returning damaged data in case data recovery is the desired outcome.
• BE14NU40 (2014, half-height)
  • The drive's firmware limits reading speeds on DVD-Video SL/DL (factory-pressed and ±R) to 12×CAV/8×CAV instead of 16×CAV/12×CAV respectively.
  • Fails reading Princo Budget DVD-R (PRINCORGM1) media entirely after trying to read the disc with what accoustically sounds like 3×CLV instead of 2×CLV on other DVD±R media.
    • PRINCORGM1 media has a purple dye rather than a cherry-red RITEKF1 type dye.
  • Although it has an excellent reading performance on damaged DVDs, its reading performance on scratched CDDA (Audio CDs) is so poor that even earliest CD players from the 1980s are able to cope with it better.
    • Even with moderate disc damage that 1980s CD players handle gracefully, the BE14NU40 tends to get hiccup-stuck and unable to find track, which is more likely to happen at lower linear speeds, while it might manage to dash through the damage uninterrupted at higher speeds.
  • On DVD-Video (including DVD±R/RW/R DL video), the drive might return data from damaged sectors as healthy to the computer, presumably to prioritize smooth playback over full data integrity.
  • Excellent CD/DVD recording quality (BluRay uncompared yet) – low error rates and good CD-RW readability on earlier CD players that usually struggle with low media reflectivity.
  • While writing CD-RW, the measured writing speed slightly slows down for a short moment (downward bulge in speed graph) once every 6 minutes (data position), starting at minute 2 (data position), then every 6 minutes until the end of the disc (2, 8, 14, 20, 26, 32, etc.), presumably to calibrate some laser parameters.
• DH18NS: One of the rare 18×CAV DVD-ROM drives. (Reading speeds on DVD±R(W) and DVD-ROM LD/±R DL are unknown.)
  • Most DVD writers since ~2007 read DVD-ROM and DVD±R at up to 16×CAV, while this signle DVD-ROM drive reads DVD-ROM at 18×CAV. Why DVD writers lack support for reading DVD-ROM at 18×CAV is unknown. They possibly would have supported it technically.

Pioneer

• All reading/writing speeds for CDs, CD-Rs and CD-RWs are limited to 40×CAV.
• Early Pioneer drives until DVR-107 (early 2004) limited VideoCD reading speeds to 4×CLV (constant linear velocity). Not even kidding.
  • Since the DVR-108 (late 2004), it is at least 10×CAV (listed as 9.3×CAV).
• DVD recorders use a variant of optical drives (e.g. DVR-R07 instead of DVR-107) with a special 40-pin ZIF (zero insertion force) connector and a miniature version of the PATA power connector.

Lite-ON

• ✅ Supports error scanning (C1/C2/PIE/PIF).
  • Appears to report higher error rates than TSSTcorp drives with the same discs.
• Ability to read data from a disc during acceleration.
  • Ability to start error scanning during acceleration, but higher error rates are reported for the part scanned during acceleration.
• No additional speed limitation for VCD and miniature (8cm) discs
• LiteON optical drives favour Z-CLV and CLV over P-CAV and CAV. Example: Slim type LiteON drive record CD-R at 24×Z-CLV instead of 24×CAV.
• LiteON slim type drives appear to have a good recording quality on CD-R and DVD±R, an above-average recording quality on CD-RW, but only a moderate recording quality on DVD±RW.
• If the last session of a CD-R is not closed, LiteON slim drives appear to lock the rotation speed to 8×CLV.
• Earlier LiteON slim drives apparently struggle detecting overburned CD-RW media

Matshita (Panasonic)

• ❌ Drives lack error scanning.
• UJ880D (2008, slim type):
  • Apparently does occasionally not write the time code of Audio CD on “SK” (vendor name) CD-RW HS media properly. The table of contents is burned properly, but CD players keep seeking indefinitely when a track is selected. (Unable to reproduce a second time) However, data discs are written properly by the model.
  • If a CD-RW is properly written, readability on earlier CD players (that usually struggle with low reflectivity media) is good.
  • Allows writing speeds of 4×CLV, 8×CLV and 10×CLV for CD-RW HS media.
  • CD-RW HS (by vendor “SK”) recording quality at 10×CLV and 4×CLV is similarly good.
  • Excellent DAE (digital audio extraction from audio CDs) quality with low noise from a highly scratched disc
    • On very heavily damaged media however, occasional skipping for a fraction of a second is hearable, which is audio of a few seconds ahead or behind the current DAE position. After this fraction of a second, it resumes the DAE at the intended position.

Odd comparisons

Reading speeds: Pioneer DVR-107 (2004) vs. TSSTcorp SH-S182 (2006)

Vendor	Model	DVD±R reading speeds	DVD-ROM DL reading speeds
Pioneer	DVR-107 (2004, half-height)	8×CAV	12×CAV
TSSTcorp	SH-S182 (2006)	12×CAV	8×CAV

As can be seen, the SH-S182 (2006) could read DVD±R faster than DVD-ROM DL, while the DVR-107 (2004) vice versa.

Reading speeds: Pioneer DVD-106 (2000) vs. HL-DT-ST GDR8162B (2003) Pioneer DVR-107 (2004)

Vendor	Model	CD-ROM	CD-R	CD-RW	DVD-ROM SL	DVD-ROM DL	CD/DVD writing
Pioneer	DVD-106 (2000)	40×CAV	40×CAV		16×CAV	Unknown	❌ No
HL-DT-ST	GDR8162B (2003)	48×CAV	40×CAV		16×CAV	8×CAV	❌ No
Pioneer	DVR-106 (2003)	32×CAV	32×CAV		12×CAV	8×CAV	✅ Yes
Pioneer	DVR-107 (2004)	40×CAV	40×CAV	32×CAV	12×CAV	12×CAV	✅ Yes

The DVR-107 (DVD writer) might have been technically capable of reaching higher reading speeds, regarding that earlier DVD-ROM (read-only) drives already reached higher reading speeds.

Media types

• While DVD-R/RW and DVD+R/RW gracefully co-exist, Blu-Ray Disc and HD-DVD sadly could not.
• HD-DVD had a DVD-RAM successor, the HD-DVD-RAM, while there has never been created such thing as a BD-RAM.
  • Although BD-RE has similar random writing capabilities as a DVD-RAM, its number of rewrite cycles is said to be just around 1000, like CD-RW and DVD±RW, while DVD-RAM media is said to have 10000 (DVD-RAM 5× speed) or even 100000 (DVD-RAM 3× speed) rewrite cycles.
• Some factory-pressed CDs have slightly off-center labels, which leads to reduced symmetry. This poor symmetry becomes noticeable as vibration that magnifies with higher disc speeds (e.g. 16×CAV and higher). Such media could damage earlier optical drives that lack vibration detection.
• Only with DVD-R and DVD-RW, the optical drive that performs the first write on blank media writes its recorder information (model number and occasionally firmware version) to the beginning of the disc.
  • Nero DiscSpeed software writes the recorder information at the end of the disc on any media type after finishing a writing test. It can be seen using a HEX editor browsing the last few LBAs (logical block addresses) of the disc.

See also

Related navigation boxes: Electronics • Mobile phones • Data storage • User experience and user interfaces

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