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1. Introduction

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LiteOn's latest release in the DVD Recorder market, the LiteOn SHW 1635S is actually an upgrade of the previously released model, the 1693S DVD-Recorder. The 1635S has been upgraded to burn +R9 (+R DL media) at the max available speed of 8X, while it can burn -R DL media at 4X. Apart from this, the drive's writing mechanism has been improved and as we will see later on in this review, all tested, burned media were burned at their specified speeds with increased quality in comparison to the previous release.

The maximum supported speed for both +R and -R media is 16X, while the drive can burn -RW and +RW media at 6X and 8X respectively.

- Features

No change has been made regarding the drive's supported features.

• SMART-BURN avoiding Buffer UnderRun errors, automatically adjusting writing strategy & running OPC to provide the best burning quality.
• SMART-X function adjusts CD-DA / VCD / DVD data extraction to a fastest allowable speed according to both data request rate from host and disk quality.
• VAS® system reduces vibration and noise during recording and reading.

- Specifications

Model	LITE-ON DVDRW SHW 1635S
DVD	Write	DVD+R 16x ( 21600 KB/sec ) maximum by CAV
		DVD+R9 8x ( 10800 KB/sec ) maximum by Z-CLV
		DVD-R 16x ( 21600 KB/sec ) maximum by CAV
		DVD-R9 4x ( 5400 KB/sec ) maximum by CLV
	ReWrite	DVD+RW 8x ( 10800 KB/sec ) by CLV
		DVD-RW 6x ( 8100 KB/sec ) by CLV
	Read	16x ( 21600 KB/sec ) maximum by CAV
	Access time	160 ms
CD	Write	CD-R 48x ( 7200 KB/sec ) maximum by CAV
	ReWrite	CD-RW 24x ( 3600 KB/sec ) maximum by Z-CLV in UltraSpeed disc
	Read	48x ( 7200 KB/sec ) maximum by CAV
	Access time	160 ms
Compatibility		Microsoft Windows 98SE / ME / 2000 / XP
MTBF ( Life )		70,000 POH
S/N Ration		> 75 dB
Environment		Operating 5C to 45C; Relative Humidity : 15% to 80%
		Non-Operating -40C to 60C; Relative Humidity : 15% to 95%
Dimension		145.0 ( W ) x 41.3 ( H ) x 170.0 ( D ) mm
Weight		< 0.9 Kg
Voltage Requirements		+5V +/-5% and less than 100 mVp-p ripple voltage
		+12V +/-5% and less than 200 mVp-p ripple voltage

Below are the drive's main specs as given by NeroInfoTool and DVDInfoPro and VSO inspector:

The drive also uses the RPC II region control, allowing a user to change the drive's region at most 5 times. As with all LiteOn drives, this one can be set to region free with the use of several utilities.

- Retail package

No changes here, as the retail package remains the same with the pervious release, that of the 1693S model. The package contains all the essentials required for a fresh start, including mounting screws, audio cable, a quick installation guide to help you through the basics of installing your device in your PC, and of course a classic Nero OEM release suite for DVD authoring writing/editing, as well as DVD playback software (Cyberlink Power DVD 5). Last but not least, the package includes an extra black bezel (front plate), offering a complete solution for both light and dark colored PC cases.

-The Drive

The external look of the drive is the same as the previous release, with the DVD+R and DVD+R DL logos and the activity led which turns green upon disc insertion. All these are also available on the black bezel.

The rear panel has the usual analogue and digital outputs (SPDIF), IDE connector and power input.

We opened the drive case to take a closer look at the inside of the drive. Opening the case voids warranty so we strongly advise against it. Click on the images below for a larger, more detailed view...

- Installation

The drive was installed under the WindowsXP OS and was recognized as "LITE-ON DVDRW SHW-1635S ". The drive came to our labs with the YSOG firmware installed which was the version used in our reading tests (DVD reading, error correction and so forth).

A few days later, LiteOn released the latest firmware revision for the 1635s, the YSON and we flashed the drive with it, which improved writing quality with certain media brands. Note here that no change was made in the reading mechanism of the drive as we confirmed with a number of tests. The latest firmware for the 1635S can be found here.

For the needs of this review, we will be posting the results of the 1635S along with the results of the NEC ND-4551A and Pioneer DVR-110, both latest releases and same specifications.

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2. Transfer Rate Reading Tests

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- CD Format

Like the 1693S, the LiteOn SHW 1635S supports up to 48X reading speed for both pressed and CDR media, while it can read USRW media at up to 32X. The following graphs show the maximum reading speed the drive managed to achieve with the various CD media, as well as the reading speeds of the comparison drives.

LiteOn drives have always been fast CD readers and the 1635S is no exception. In the CD reading tests, the results of which are shown above, the reviewed drive managed to achieve the fastest reading speed managing 37.67X average speed compared with 36.36X and 32.07X for the NEC and Pioneer drives respectively. With USRW media, the NEC reported the fastest reading speed due to its max 40X supported speed.

- DVD Format

We repeated the reading tests, this time using a collection of pressed SL and DL DVD media to test the drive's reading capabilities with DVD media and we present the results in the graphs below.

All three drives support up to 16X reading speed with Pressed SL media, hence the difference in speed is negligible.

The two layers of a PTP DVD-ROM disc are read sequentially with the drive starting reading from the inner part of the disc, which is the beginning of each layer, progressing towards the outer range, for each layer. Max supported speed with the 1635S is 8X, while with the NEC and Pioneer drives, max supported speed is 12X.

The graph above shows the reading performance of the drive with OTP dual layer media. The first layer of an OTP dual layer DVD-ROM is read exactly the same way as the first layer of the PTP disc tested previously. The difference here is the reading strategy of the second layer of the disc. The beginning of the second layer is located in the outer part of the disc, so the drive starts reading from the outer tracks towards the inner part of the disc. Similar performance in this case due to the 8X max reading speed with DL media.

With Write-Once media, the 1635S reported lower reading speeds than the NEC drive which was fastest. With ReWritable media, the LiteOn and NEC drives reported similar speeds while the Pioneer drive was left behind. In general, speeds with DVD +/- R and RW media were very consistent at just above 9X from the LiteOn drive.

Even though the ripping speed is not the highest, it is nonetheless a fast speed.

Overall, good reading capabilities, excellent CD reader and a fast DVD reader.

- Appendix

Nero CD-DVD Speed Graphs

• CD Pressed / CD-R / US-RW
• DVD Pressed SL / DVD Pressed PTP DL / DVD Pressed OTP DL / DVD-R / DVD-RW / DVD+R / DVD+RW

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3. CD Error Correction Tests

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In the following tests, we check the drive's behavior when it comes to reading scratched / defective discs. The test discs we use are the ABEX series from ALMEDIO.

- ABEX TCD-721R

Errors total	Num: 776367
Errors (Loudness) dB(A)	Num: 46459	Avg: -73.9 dB(A)	Max: -20.6 dB(A)
Error Muting Samples	Num: 2487	Avg: 1.0 Samples	Max: 8 Samples
Skips Samples	Num: 0	Avg: 0.0 Samples	Max: 0 Samples
Total Test Result	77.1 points (of 100.0 maximum)
C2 Accuracy	99.6 %

With a low total error count and no skipped samples, the drive's error correction mechanism seems to be very good in this CD error correction test.

- ABEX TCD-726

Errors total	Num: 66
Errors (Loudness) dB(A)	Num: 11	Avg: -77.5 dB(A)	Max: -69.4 dB(A)
Error Muting Samples	Num: 0	Avg: 0 Samples	Max: 0 Samples
Skips Samples	Num: 0	Avg: 0 Samples	Max: 0 Samples
Total Test Result	93.3 points (of 100.0 maximum)
C2 Accuracy	100 %

Surprisingly enough, the drive did not manage to achieve a flawless 100 points result, as is the case with many of the best drives with this test disc. Nevertheless, the result is satisfactory.

- CD-Check Audio Test Disc

The CD-Check Test Disc is a very useful tool for evaluating the Sound Reproduction / Error correction capabilities of a CD player. The disc offers a signal combination with disc error patterns to rate the drive's ability to read music and reproduce it completely. Five tracks on the disc contain a sequence of progressively difficult tests. These tracks are referred as Check Level -1 through Check Level -5.

The tracks are reproduced (played) through a software multimedia player (e.g. Windows Media Player). Each level is considered as passed, if the tone coming out from the speakers is smooth, continuous without interruptions, skipping or looping. The higher the Check Level passed, the more reliable the sound reproduction of the tested device.

Error Level	1	2	3	4	5
LiteON SHW-1635S	5/5	5/5	5/5	0/5	0/5

The drive passed only the first three Check Levels of the test. The performance reveals average performance with the specific test disc. The fourth and the fifth levels include an error size of 1.125mm and 1.500mm respectively, and the drive produced continues audible clicks over those tracks.

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4. DVD Error Correction Tests

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In the following tests, we examine the DVD reading capabilities of the LiteOn SHW-1635S drive with scratched / defective DVD media. For the tests we used CDVD Benchmark and Nero CDSpeed. The reference test media comes from ALMEDIO.

- Single Layer media

ABEX TDR-821

This is a single sided, single layer DVD-ROM with 4.7GB capacity, and its surface has an artificial scratch of dimensions varying from 0.4 to 3.0 mm. The following transfer rate picture comes from the CDVD Benchmark v1.21 transfer rate test.

Excellent reading, with no drops in speed and the drive managed to reach its max reading speed of 16X.

ABEX TDR-825

This is also a single sided, single layer DVD-ROM of 4.7GB capacity. The data structure of the disc is exactly the same as that of the TDR-821, with the difference that there are no scratches on it but instead, defective areas of dimensions ranging from 0.5 to 1.1 mm. There are also fingerprints sized between 65 and 75 micrometers.

Typical reading graph for all LiteOn drives, where the reading speed drops at the beginning of the second defective area, while it managed to complete the test without any significant reading anomalies. Once again, all the way up to 16X.

- Dual Layer media

ABEX TDR-841

This is an 8.5GB dual layer, single sided DVD-ROM disc with artificial scratches of dimensions ranging from 0.4 to 3.0mm, on both layers.

Excellent performance. Both layers were read without errors. Note here that due to the max supported reading speed for DL media, the drive maxed out at 8X.

ABEX TDR-845

This test disc is a single sided, dual layer DVD-ROM disc with a capacity of 8.5GB. The only difference between the TDR-845 and the TDR-841 discs is that the first includes defective areas and fingerprints. The dimensions of the defective areas ranges from 0.5 to 1.1 mm and the fingerprints are sized from 65 to 75 micrometers.

Last graph, and the hardest to read, with two layers and four defective areas (two on each layer) and the LiteOn 1635S did quick work of this test media, reading it flawlessly once again, with only a drop in reading speed reported near the beginning of the second defective area on both layers. Seems like the fingerprints present a minor obstacle for the drive. Other than that, we can say that we have a job well done.

ABEX TDV-541

The TDV-541 is a single sided, dual layer DVD-VIDEO disc, with a capacity of 8.5GB. The disc is based on the TDV-540 series which is designed for inspection and adjustment of DVD-VIDEO players. The disc checks the layer switch operation from layer 0 to layer 1 and also includes test pictures and test signals for DVD sound files. The current TDV-541 also checks the error correcting capabilities of the drive and includes scratches from 0.4 to 3.0 mm.

Excellent performance with this test media. Not much else to point out here as the above graph speaks for itself.

ABEX TDV-545

The TDV-545 disc is based on the TDV-540 series. It is a single sided, dual layer DVD-VIDEO disc with a capacity of 8.5GB. The TDV-545 includes artificial black dots on the data surface, sized from 0.4 to 1.0 mm. It also has 65 - 75 micrometer fingerprints.

Once more, the drive showed its best when reading this media.

- Conclusion

All the above tests indicate a very good error correction mechanism, with fingerprints being the only defect the 1635S has any problem with, if it can be considered that. The drive successfully completed all reading tests.

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5. Protected Disc Tests - Reading Tests

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Using Alcohol 120% on three protected discs, with the appropriate settings depending on the protection type of each disc, we measured the duration and transfer rate of the protected media. The results are given below.

 

Game Title	">Protection Scheme	Duration	Reading speed
PSX "NBA Jam Extreme"	Lybcrypt	3:03 min	430 sectors/sec
Serious Sam The Second Encounter	SafeDisc v.2.50.051	13:11 min	424 sectors/sec
VRally II	SecuROM v.2	2:20 min	2455 sectors/sec

 

Not much has changed from the previous drive, the 1693S. Ripping speeds are more or less the same and in keeping with tradition, LiteOn drives continue to be fast safedisc rippers.

- Writing Tests

The LiteON SHW-1653S supports the DAO-RAW writing mode. For checking the drive's EFM correction status, we used 3 different game titles with different SafeDisc 2 versions having the latest software patches installed. After making the images of the various titles onto the hard disk, we burned them (at maximum speed) with Alcohol 120% v1.9.2.1705. Two different discs were created for each title - one with the "Rectify Sub-Channel Data" enabled and one more with the function disabled.

• Fifa 2004 - Safe Disc v3.1x
• The Sims Superstar - Safe Disc v2.9x
• The Sims Unleashed - Safe Disc v2.8x
• Serious Sam Second Encounter - Safe Disc v2.51.021
• Max Payne - Safe Disc v2.51.020

The table below shows the results of the attempted backups and whether they worked (game installed / played normally), or not.

Drive	Fifa 2004 SD v3.1x		Sims Superstar SD v2.9x		Sims Unleashed SD v2.8x		Serious Sam-Second Encounter SD v2.50.051		Max Payne SD v2.51.020
	EFM OFF	EFM ON	EFM OFF	EFM ON	EFM OFF	EFM ON	EFM OFF	EFM ON	EFM OFF	EFM ON
Liteon 1653s	No				Yes

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6. DAE Tests

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- Pressed and CDR AudioCD

Using pressed AudioCD and its CD-R copy made with with EAC, we have the following results:

The LiteOn 1635S proved to be the fastest among the three drives, with both Pressed CD and CDR media.

-Advanced DAE Quality

Once more, the LiteOn was the fastest and reported a quality score of 100.

As reported by the advanced DAE quality test, the drive can read CD Text, Subchannel Data, and Leadin-Leadout.

- Reading 90/ 99mins AudioCDs

• 90min AudioCD

Unfortunately, the drive could not read the 90min Audio CD, reporting the above error message.

• 99min AudioCD

Even though the drive reached close to the end of the reading process, it could not successfully complete the test, reporting the above error message.

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7. Protected AudioCDs

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For the test procedure, we used three audio discs with different audio copy protections. The ripping process on all protected audio discs was carried out with Exact Audio Copy v0.9 beta5.

The tested protected Audio discs were:

Audio Discs	Protection
Celine Dion - New Day Has Come	Sony's Key2Audio
Natalie Imbruglia - White Lilies Island	Cactus Data Shield 200
Aiko Katsukino - The Love Letter	Cactus Data Shield 200.0.4 - 3.0 build 16a

The Cactus Data Shield 200, contains artificial errors that are not easily bypassed by the reader, while the Key2Audio contains a second session causing problems for readers when trying to read the Table Of Contents (TOC).

The LiteOn drive recognized up to the 12th Audio track of the CDS200 disc,

and with the "Retrieve Native TOC" option removed, the 13th Data track was also recognized.

The test results are shown in the following table:

LiteOn SHW 1635S	Key2Audio	CDS200
	Ripping process completed, EAC reports no problems, Read&Test CRC comparison successful for all tracks	Ripping process completed, EAC reports no problems, Read&Test CRC comparison successful for all tracks

With Key2Audio discs, EAC didn't report any timing problems and at the same time, Read&Test CRC check comparison was the same for corresponding tracks. The drive could not rip 100% accurately the CD200 disc where Read&Test CRC check comparison was not the same for corresponding tracks.

- Cactus Data Shield 200.0.4 - 3.0 build 16a (Aiko Katsukino - The Love Letter)

This is a "special" CDS200 build, since it doesn't contain any artificial errors during the ripping process. Most problems occur when trying to write the ripped wav files, since the produced CD-R disc contains C2 and CU errors! This "problem" is rumored to be connected with specific chipset weaknesses.

We ripped the disc contents with EAC and burned the wav file produced from the Cactus Data Shield 200.0.4 - 3.0 build 16a disc with the latest Nero version as AudioCD+CD-Text. The burned media was checked for C1/C2 errors and for BETA/Jitter errors with PlexTools software using Plextor PX-716A.

 

LiteOn SHW 1635S	CDS 200.0.4 - 3.0 build 16a
	Reading performed without any errors.

- C1C2 Error rate from PleXWriter PX-716A (8X CLV reading speed)

As it can be clearly seen from the C1/C2 Plextools graph, the drive managed to produce a disc with few C1 errors, while no C2 were reported.

- BETA/Jitter Error rate from PleXWriter PX-716A

We then tried to extract all wav files with the Plextor PX-716A and PlexTools DAE Error Correction 5th Level enabled:

No reading errors were reported after extracting all files.

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8. CD Recording Tests

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As with the previous LiteOn releases, the SHW-1635S supports up to 48X writing speed with CD media, while it supports up to 24X with CD-RW.

• CD-R Format

According to Nero CDSpeed, the drive confirmed its maximum 48X speed. The test started at 21.82X and finished at 48.89X, having an average speed of 37.06X. Click on the image below for an enlarged view.

• CD-R Recording Times

For the burning tests, we created an 80min data compilation through Nero Burning Rom, recording the data on several 700MB discs. The LiteON SOHW-1693S needed only 2:38 minutes to complete this task at the maximum 48X writing speed.

In the following graph, we can see the recording times the LiteOn 1635S reported with various CD-R media inserted.

- Overburning Test

The drive supports overburning up to 99mins.

• CD-RW Format

The LiteON SOHW-1635S supports 24X Z-CLV rewriting speed with Ultra Speed Rewritable Media (US-RW).

Below you can see the Nero CD-DVD Speed writing simulation test with blank 24X US-RW media from Mitsubishi Chemicals.

The drive starts the writing task at 15.99X and steps up to a maximum of 24.00X with an overall average speed of 22.48X.

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9. C1 / C2 Error Measurements

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We measured the C1 / C2 error rate on the recorded discs we burned at the maximum supported writing speed of 48X. The software we used was PleXTools Professional v2.25, and more specifically, the built-in Q-Check utility. The reader was the Plextor PX-716A (firmware v1.09).

• BenQ 80min 52X @ 48X

• Intenso 80min 52X @ 48X

• MMore 80min 52X @ 48X

• Traxdata 80min 52X @ 48X

• TY 80min 48X @ 48X

- Summary

According to the above Plextools scans, the LiteOn 1635S produced some good quality burns, with almost no C2 errors. Some C2 errors were reported with BenQ, Intenso and quite an amount of them with Traxdata media. Now let us continue on to the next page and the Clover CDX tests.

- Appendix

• Media ID codes

Media Label	Manufacturer Name	Lead Out TIme
BenQ 52X	Ritek	79m59s70f
Intenso 52X	Prodisc	79m59s71f
MMore 52X	Moser Baer India	79m59s74f
Traxdata 52X	Ritek	79m59s70f
TY 80min 48X	Taiyo Yuden	79m59s72f

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10. Writing Quality Tests - Clover System Tests

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The Clover Systems CDX Compact Disc Analyzer is a high-speed tool to quantitatively measure the quality of a CD. It will analyze CD-DA, CD-ROM, CD-ROM XA, CD-I, CD-R, Photo-CD, Enhanced CD and CD-RW discs at 4X, 8X, 24X, 32X or 40X speed. It effectively measures disc quality by examining the quantity and severity of CIRC errors generated during playback. It also provides the capability to measure signal parameters related to pit geometry, such as asymmetry and reflectivity. Together, all these bits of information provide a thorough analysis of disc quality. The Clover Systems Analyzers can also perform various format-checking tests on data discs, and do bit-for-bit data comparison on all types of CDs. All tests are carried out at the maximum speed of 40X.

CIRC error correction uses two principles to detect and correct errors. The first is redundancy (extra information is added, which gives an extra chance to read the disc), and the second is interleaving (data is distributed over a relatively large physical area). The CIRC error correction used in CD players uses two stages of error correction, the well known C1 and C2, with de-interleaving of the data between the stages.

The error type E11 means one bad symbol was corrected in the C1 stage. E21means two bad symbols were corrected in the C1 stage. E31 means that there were three or more bad symbols at the C1 stage. This block is uncorrectable at the C1 stage, and is passed to the C2 stage. Respectively, E12 means one bad symbol was corrected in the C2 stage and E22 means two bad symbols were corrected in the C2 stage. E32 means that there were three or more bad symbols in one block at the C2 stage, and therefore this error is not correctable.

BLER (Block Error Rate) is defined as the number of data blocks per second that contain detectable errors, at the input of the C1 decoder. Since this is the most general measurement of the quality of a disc, you will find BLER graphs for all media tested below. If you click on the images you can see a more detailed table, indicating error levels. The Red Book specification (IEC 908) calls for a maximum BLER of 220 per second averaged over ten seconds. Discs with higher BLER are likely to produce uncorrectable errors. Al low BLER shows that the system as a whole is performing well, and the pit geometry is good. However, BLER only tells us how many errors were generated per second, and it does not tell us anything about the severity of those errors.

• BenQ 80min 52X @ 48X

• Intenso 80min 52X @ 48X

• MMore 80min 52X @ 48X

• Traxdata 80min 52X @ 48X

• TY 80min 48X @ 48X

- Summary

As we can clearly see from the above table, MMore and TY media were the only two that passed the clover system test, confirming the Plextools graphs in the previous page (no C2 reported for either of these media).

- Appendix

Media Label	Manufacturer Name	Lead Out TIme
BenQ 52X	Ritek	79m59s70f
Intenso 52X	Prodisc	79m59s71f
MMore 52X	Moser Baer India	79m59s74f
Traxdata 52X	Ritek	79m59s70f
TY 80min 48X	Taiyo Yuden	79m59s72f

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11. DVD Recording Tests

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• 16X DVD+R Single Layer writing

• 16X DVD-R Single Layer writing

The drive completed successful DVD-R writing at 16X in 5:30mins. The test started at 6.69X, reached a maximum writing speed of 15.95X and reported an average speed of 11.93X.

- Burning Tests

• DVD-R media

We burned a variety of DVD-R media rated as 16X and 8X as shown in the above table. All media were burned at their stated speed, while best burn (i.e. fastest burn) came with the BenQ media @ 16X burned in 5:47mins.

• DVD+R media

Once more, all media were burned at their stated speed. Note here, that the BeALL media was burned at 4X. Best time came with Verbatim 16X, burned in 5:56mins.

- Comparison with other drives

With write-once media, the LiteOn drive proved to be the fastest.

With re-writable media, all drives reported more or less the same speeds, with negligible differences between them.

- DVD Overburning Test

• DVD+R

• DVD-R

Unfortunately, the drive does not support DVD overburning for both -R and +R media formats, producing the above error messages.

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12. CDSpeed/PlexTools Scans - Page 1

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In order to test the writing quality and readability of the burned media we used two readers with two software applications:

In general, a "perfect" disc should have a smooth reading curve, very low PIE/POE and zero (0) POF error rates. Most times however, even though a disc has very low PIE/POE error rates, the reading curve may not be smooth containing dropoffs. Due to the fact that we overspeed the reading capabilities of the LiteON SOHD-167T, such drops are expected, especially near the outer area of the disc.

The measurements below should be taken not as the absolute criteria of the burning quality, but as an indication level.

16X DVD+R Writing Speed

- BenQ 16X DVD+R @ 16X

- CMC 16X DVD+R @ 16X

- MMore 16X DVD+R @ 16X

- Optodisc 16X DVD+R @ 16X

- Philips 16X DVD+R @ 16X

- Prodisc(1) 16X DVD+R @ 16X

- Prodisc(2) 16X DVD+R @ 16X

- Ricoh 16X DVD+R @ 16X

.

- Ridisc 16X DVD+R @ 16X

- Traxdata 16X DVD+R @ 16X

- Verbatim 16X DVD+R @ 16X

- Summary

According to the above measurements, most media reported low PI values below, the 280 limit, while most CD-Speed graphs were far from smooth and linear.

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13. CDSpeed/PlexTools Scans - Page 2

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In order to test the writing quality and readability of the burned media we used two readers with two software applications:

In general, a "perfect" disc should have a smooth reading curve, very low PIE/POE and zero (0) POF error rates. Most times however, even though a disc has very low PIE/POE error rates, the reading curve may not be smooth containing dropoffs. Due to the fact that we overspeed the reading capabilities of the LiteON SOHD-167T, such drops are expected, especially near the outer area of the disc.

The measurements below should be taken not as the absolute criteria of the burning quality, but as an indication level.

8X DVD+R Writing Speed

- BeAll 8X DVD+R @ 4X

- BenQ 8X DVD+R @ 8X

-CMC 8X DVD+R @ 8X

- Datawrite 8X DVD+R @ 8X

- Maxell 8X DVD+R @ 8X

- MMore 8X DVD+R @ 8X

- Optodisc 8X DVD+R @ 8X

- Prodisc 8X DVD+R @ 8X

- Ricoh 8X DVD+R @ 8X

- Traxdata 8X DVD+R @ 8X

- TY 8X DVD+R @ 8X

- Summary

With 8X effective DVD+R media, the LiteOn produced some good burns according to the reported results with the Plextools and CD-Speed Utilities. Best burn came with the Prodisc media with low PI values and a smooth scan graph.

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14. CDSpeed/PlexTools Scans - Page 3

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In order to test the writing quality and readability of the burned media we used two readers with two software applications:

In general, a "perfect" disc should have a smooth reading curve, very low PIE/POE and zero (0) POF error rates. Most times however, even though a disc has very low PIE/POE error rates, the reading curve may not be smooth containing dropoffs. Due to the fact that we overspeed the reading capabilities of the LiteON SOHD-167T, such drops are expected, especially near the outer area of the disc.

The measurements below should be taken not as the absolute criteria of the burning quality, but as an indication level.

16X DVD-R Writing Speed

- BenQ 16X DVD-R @ 16X

- Optodisc 16X DVD-R @ 16X

- Philips 16X DVD-R @ 16X

- Prodisc(1) 16X DVD-R @ 16X

- Prodisc(2) 16X DVD-R @ 16X

- Traxdata 16X DVD-R @ 16X

- Verbatim 16X DVD-R @ 16X

- Summary

As we can see from this page, the burning quality is very dependent on the inserted media, where Verbatim media proved to be the best burned media at 16X. Average quality according to most CD-Speed graphs.

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15. CDSpeed/PlexTools Scans - Page 4

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In order to test the writing quality and readability of the burned media we used two readers with two software applications:

In general, a "perfect" disc should have a smooth reading curve, very low PIE/POE and zero (0) POF error rates. Most times however, even though a disc has very low PIE/POE error rates, the reading curve may not be smooth containing dropoffs. Due to the fact that we overspeed the reading capabilities of the LiteON SOHD-167T, such drops are expected, especially near the outer area of the disc.

The measurements below should be taken not as the absolute criteria of the burning quality, but as an indication level.

8X DVD-R Writing Speed

- BenQ 8X DVD-R @ 8X

- Bulkpaq 8X DVD-R @ 8X

- Datawrite 8X DVD-R @ 8X

-Maxell 8X DVD-R @ 8X

- MMore 8X DVD-R @ 8X

- Optodisc 8X DVD-R @ 8X

- Prodisc(1) 8X DVD-R @ 8X

- Prodisc(2) 8X DVD-R @ 8X

- Ridisc(Red) 8X DVD-R @ 8X

- Ridisc(Blue) 8X DVD-R @ 8X

- TY 8X DVD-R @ 8X

- Summary

At 8X burning speed with 8X certified DVD-R media, the burning quality has improved. Low PI Values and some smooth CD-speed graphs indicate good quality burns.

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16. CDSpeed/PlexTools Scans - Page 5

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• MKM DVD+RW 8X @ 8X

• Traxdata DVD-RW 6X @ 6X

• Verbatim DVD-RW 6X @ 6X

- Summary

Average burning quality. A future firmware release with improvements regarding these media would be welcomed.

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17. Writing Quality Tests - Almedio AEC-1000

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The AEC-1000 consists of a DVD Drive and the "ALChecker" error measurement application which can check the written data quality. The application is capable of 1X CLV measurement as well as 4X CLV on DVD-Video/ROM and finalized DVD+R/-R media.

There are three measurement modes:

• Fine Mode: checks a series of eight consecutive ECC blocks,
• Rough Mode: checks eight consecutive ECC blocks every 100h ECC blocks
• Quick Mode: checks three specified areas

The checking status is shown graphically in real time while you can save the error graph at the end of the test. The reported errors are the PI and the UncPO. In the case of PI, it counts the number of rows corrected by the PI error correction in each group of eight consecutive ECC blocks. In the case of UncPO, it counts the number of ECC blocks in which more than one byte is uncorrectable in eight consecutive ECC blocks. For our quality scans, we set for 1X CLV and Fine Mode which is the slowest and with the safest results. Also, we chose to measure all the media burned at the maximum available writing speed, namely 16X.

- BenQ 16X DVD+R @ 16X

- Verbatim 16X DVD+R @ 16X

- MKM 16X DVD-R @ 16X

- Optodisc 16X DVD-R @ 16X

- Prodisc(2) 16X DVD-R @ 16X

- Traxdata 16X DVD+R @ 16X

Five out of six tested media reported good quality. Good performance by the LiteOn 1635S DVD-Burner.

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18. DVD+R DL - Page 1

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We burned some DVD+R DL and DVD-R DL discs with data content. For this task we used "Create Data Disc" from Nero CDSpeed in order to fully burn the discs.

Traxdata DVD+R DL 2.4X @ 2.4X

The drive started burning the media at 2.47X and maxed out at 2.48X with an average of 2.47X using CLV writing strategy. Burning ended after 43:34mins.

Verbatim DVD+R DL 2.4X @ 8X

Using Z-CLV writing strategy, burning started at 4.04X reaching a max speed of 8.02 and reporting an average speed of 6.94X. Writing ended after 16:59mins.

Traxdata DVD-R DL 4X @ 4X

With Traxdata DVD-R DL 4X and CLV writing strategy, the test started at 4.00X and maxed out at 4.03X, reporting an average speed of 4.01X and a completion time of 27:35mins.

Verbatim DVD-R DL 4X @ 4X

The test started at 4.00X and writing speed maxed out at 4.03X with an average speed of 4.01X, completing the burn in 27:33mins.

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19. DVD+R DL - Page 2

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In order to test the LiteOn SHW 1635S DL writing quality, we used the LiteOn SOHD-167T and the Plextor PX-716A drives to scan the burned media.

Traxdata DVD+R DL 2.4X @ 2.4X

According to Plextools, the first layer was of good quality with values below the 280 limit. After the layer change though, the values went sky high, reaching all the way up to 640 POE. This is not necessarily a bad quality burn and can be characterised as average.

Verbatim DVD+R DL 2.4X @ 8X

With Verbatim DVD+R DL 2.4X @ 8X media, the writing quality was improved and the drive managed to produce a good quality burn.

Traxdata DVD-R DL 4X @ 4X

According to CD-Speed, the above burn is good quality, even though Plextools reports high PI values during the layer change.

Verbatim DVD-R DL 4X @ 4X

Once more, good quality burn with Verbatim media.

- Summary

The writing quality is dependent on the media brand used. Verbatim media reported good results while we have average performance when using Traxdata media.

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20. 1635S vs SA300 - Page 1

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For checking exactly what the SHW-1635S reports, we used three different media, burned with other recorders. The three media have been measured with the well known AudioDev SA300 DVD CATS system at 1X.

The drive is capable of reporting PI/PIF errors, so we will compare those measurements at 8X reading speed.

Please note that the posted results are only valid for the specific tested LiteON SHW-1635S drive. Using other drives, even another SHW-1635S, can produce totally different results. Be aware!

#1st Test Disc - PISum8/PIF Comparison - 8X Reading speed

From the above graphs, we can see that the error line trend follows the same pattern as the original CATS scans.

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21. 1635S vs SA300 - Page 2

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For checking exactly what the SHW-1635S reports, we used three different media, burned with other recorders. The three media have been measured with the well known AudioDev SA300 DVD CATS system at 1X.

The drive is capable of reporting PI/PIF errors, so we will compare those measurements at 8X reading speed.

Please note that the posted results are only valid for the specific tested LiteON SHW-1635S drive. Using other drives, even another SHW-1635S, can produce totally different results. Be aware!

#2nd Test Disc - PISum8/PIF Comparison - 4X Reading speed

In this case, the graph pattern differs from the CATS error line pattern.

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22. 1635S vs SA300 - Page 3

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For checking exactly what the SHW-1635S reports, we used three different media, burned with other recorders. The three media have been measured with the well known AudioDev SA300 DVD CATS system at 1X.

The drive is capable of reporting PI/PIF errors, so we will compare those measurements at 8X reading speed.

Please note that the posted results are only valid for the specific tested LiteON SHW-1635S drive. Using other drives, even another SHW-1635S, can produce totally different results. Be aware!

#2nd Test Disc - PISum8/PIF Comparison - 4X Reading speed

The trend line reported by the 1635S follows the CATS trend line.

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23. 1635S vs SA300 - Page 4

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For checking exactly what the SHW-1635S reports, we used three different media, burned with other recorders. The three media have been measured using the well known AudioDev SA300 DVD CATS system at 1X.

The drive is capable of reporting PI/PIF errors, so we will compare those measurements at 8X reading speed.

Please note that the posted results are only valid for the specific tested LiteON SHW-1635S drive. Using other drives, even another SHW-1635S, can produce totally different results. Be aware!

#3rd Test Disc - PISum8/PIF Comparison - 4X Reading speed

And lastly, a somewhat close trend line to the original CATS.

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24. BookType Setting

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All LiteOn based drives support the Booktype setting, allowing the user to maximize compatibility. Users should change to the preferred booktype setting prior to burning +R, +RW or +R9 media.

In order to achieve a booktype setting change, we used the well known to LiteOn users booktype utility, BookType 1.3.5. We used a blank DVD+RW media and managed to change its booktype to DVD-ROM as seen in the following screenshots.

Prior to change...

And with the booktype changed successfully.

In order to change the media to DVD-ROM booktype, we must write the information on the media prior to burning with the "Write now!" function, else it will not be recognized as such by any drive.

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25. Conclusion

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LiteOn's latest release, the DVDR SHW-1635S is mainly an upgrade of the previous release, the 1693S. The drive offers a higher R9 writing speed, reaching up to 8X for the +R DL media and 4X for the -R media. Apart from this, writing quality has been improved and with the recent firmware upgrade, version YSON, writing quality has been further improved with certain media. Although this is good, DL quality must be checked and improved with a future firmware. But let's start from the beginning.

With CD reading speed, it has become standard that LiteOn drives are among the fastest, if not the fastest DVD-Burner readers available on the market today. So, the 1635S can read any inserted media at a speed up to 48X for all CD formats. In the Error correction department, the LiteOn 1635S has a good position. Even though CD error correction is not as good as expected, DVD error correction is pretty good, almost great. So, no problems there and owner of defective media can rest easy.

A good question would be "did LiteOn improve protected media ripping capabilities"? Unfortunately, the answer is no. The ripping capabilities of the 1635S are almost the same as the 1693S, almost to the sec. As seen in the preview pages, the drive cannot accurately backup SafeDisc2 v2.9x+ protected discs. Protected audio media ripping remains the same too, which in this case is a good thing because of the drive's ability to successfully rip and backup all tested media.

Moving on to burning quality and CD quality in specific. The drive managed to produce good quality CD burns according to Plextools, while the CDX Clover Systems scan indicated two out of five burned media as "pass". These two media were the ones with no C2 reported during the Plextools scans. DVD burning quality has improved from the previous model. All inserted media were burned at their stated speeds. Note here, that as it can be seen from the quality measurements pages in this review, the burning quality is much dependent on the inserted media brand.

With DVD±RW media, the burning quality is not satisfactory, though it is not a drive of bad quality burns. Further improvement with a future firmware would be welcomed. Lastly, DL writing quality was good, though once more, very dependent on media brand used. A firmware upgrade is welcomed to improve this minor issue too.

When it comes to features, the LiteOn 1635S can claim the most complete title as far as the "basics" are concerned. The Bitsetting feature is fully supported with all DVD+ media (+R,+RW,+RDL) and the user can change the booktype to the desired type prior to burning in order to maximize compatibility with stand alone players. The Region Free option is also available. Last but no least, the retail package includes an extra black bezel, enabling the user to change the drives "look" in order to suit his needs.

The price at the time of the review for the retail package of the LiteOn SHW-1635S burner was close to US$43 at newegg.com.

- The Good

• Good DVD error correction
• Supports protected Audio discs
• Fast CD Reader
• Bitsetting for all media (+R, +RW, +R9)
• Region free utilities
• Can be used for DVD media error measurements

- The Bad

• Doesn't accurately backup SafeDisc2 v2.9x+ protected discs
• Doesn't support DVD overburning
• Cannot read 90/99min audio discs

- Like to be fixed

• Improved DVD writing quality with specific media

 

Retail Package
Reading
Error Correction
Protected Discs
Writing
Features