Lite-On DX-20A4PU 20x EZ-DUB DVD±RW/RAM

In the fall of 2005, Lite-On introduced its first EZ-DUB enabled DVD writer, the SOHW-1673SU. This innovative drive gave users the ability to duplicate a disc or backup their data by pressing a button and following a few simple steps. One of the latest additions to the EZ-DUB line is the DX-20A4PU. Based on the DH-20A4P, this external drive is capable of 20x DVD±R, 8x DVD+RW, 6x DVD-RW, 8x DVD±R DL and 12x DVD-RAM writing speeds and a maximum DVD read speed of 16x. The DX-20A4PU also features many of the technologies we've come to expect from Lite-On including more advanced ones like SmartWrite and OverSpeed.

With features and specs like this, the DX-20A4PU sounds like it has a lot of potential. To give you an idea of what to expect from Lite-On's new external writer, we'll take a look at its features and then see how it compares to some of the 20x DVD±RW drives from the competition. Does the DX-20A4PU have what it takes? Keep reading as we find out.

What's in the box?:

• Lite-On DX-20A4PU "EZ-DUB" 20x DVD±RW/RAM Drive
• Nero Software CD
• User's Manual
• Quick User's Guide
• USB 2.0 Cable
• AC Power Adapter
• 1 Taiyo Yuden 16x DVD+R Disc
• 1 Taiyo Yuden 16x DVD-R Disc
• Drive Stand
• Warranty Information

Physical Features:

The drive Lite-On sent us for this review was manufactured in November of 2007 and had firmware 9P59.This is the newest firmware currently available for the DX-20A4PU.

By looking at the front of the DX-20A4PU you can see that it is based on Lite-On's internal 20x DVD±RW, the DH-20A4P. The two drives not only share the same bezel design, but many of the same logos. Along with the large Lite-On logo, you can see a few showing support for the DVD+ReWritable and DVD Multi specifications, as well as Ultra Speed CD-RW media.

The DX-20A4PU's enclosure is radically different from Lite-On's previous EZ-DUB drives. Relatively compact for an external DVD writer, it measures only 168mm x 57.5mm x 197.71mm and weighs in at 1.1kg. The top, bottom and one side of the drive are also covered with glossy black plastic. While this gives the DX-20A4PU a more sophisticated look, finger prints and smudges have a tendency to stand out.

On the top of the DX-20A4PU you can see a large "EZ-DUB" logo and a pair of touch sensitive buttons. The "DUB" and "FILE" buttons glow a neon blue when in operation and are used to control the drive's EZ-DUB function. On the bottom, you can see that the DX-20A4PU has four small rubber feet to keep it from sliding around when placed on a flat surface.

The rear of Lite-On's new external drive has its share of connectors. Starting from the left, you can see its USB 2.0 connector, on/off switch and power connector.

Technical Specs:

The specs below have been taken from Lite-On's website and the documentation that came along with the drive.

EZ-DUB:

The DX-20A4PU is one of the latest drives from Lite-On to feature their EZ-DUB technology. Using the included EZ-DUB software and the buttons located on top of the drive, users can quickly and easily duplicate a disc or backup their data. According to Lite-On, it's as easy as press, burn and go.

To initiate the backup process, press the "FILE" button on top of the DX-20A4PU. The EZ-DUB window pictured below will then pop up on your desktop. Simply drag and drop the files you want to backup onto the icon. This icon will automatically determine the type of media required (CD, DVD or DVD DL), depending on the amount of data.

When you're done adding files, insert a blank disc into the drive and press the "FILE" button once again. The EZ-DUB software will then check the disc type and source files and then start writing the data at the media's maximum speed. When it's done, the disc automatically ejects. If you'd like to make another copy, just pop in another blank disc. Otherwise, EZ-DUB's cache will be cleared.

Copying, or "dubbing", a disc is an even simpler process. To start, put the source disc in the drive and press the "DUB" button. The EZ-DUB software will then read the disc and copy an image of it to your hard drive. When it's done, insert a blank disc in the drive. The software will then burn the image to disc.

The DX-20A4PU features what Lite-On calls SmartWrite technology. Previously known as HyperTuning, SmartWrite automatically creates writing strategies for unknown, or unsupported, DVD±R and DVD±R DL media. Simply enable SmartWrite, insert your disc and burn. The new writing strategy is then created on-the-fly.

SmartWrite also works with supported media. When enabled, the drive will ignore the writing strategy stored in the firmware and instead create a new one. This is very useful if you are trying to record a disc that uses another company's MID code (I.E. fake TYG02 code discs).

OverSpeed:

The DX-20A4PU also supports Lite-On's OverSpeed function. When enabled, the drive will try to write to your DVD±R media at a speed higher than what would normally be supported. To do this, OverSpeed relies heavily on SmartWrite. When a disc is written at a higher than normal speed, SmartWrite will automatically create a new writing strategy for it.

I should point out that OverSpeed does have some limitations. To prevent people from writing to all DVD±R media at 20x, the writing speed can only be bumped up one level. For example, if your disc was normally supported at 16x, the DX-20A4PU would now give you the option to write to it at 18x.

More Features:

By looking at the picture below, you can see that Lite-On's new DVD writer is identified as an "ATAPI DVD A DH20A4P."

Nero also shows that the DX-20A4PU has a maximum CD writing speed of 48x and a 2048KB buffer. This buffer is backed up by Super-Link buffer underrun protection as well. According to Nero, the DX-20A4PU can also write CD-Text and overburn. When testing the drive's capacity, it had no problems overburning up to 99 minutes with our CompUSA media.

Using Alex Noe's Weak Sector Utility we were able to determine that the DX-20A4PU is a "two sheep" burner and is capable of backing titles protected by SafeDisc 2.90. Like most drives, it did not pass the "three sheep" test.

Here is a screen shot from Nero's InfoTool. This program queries the drive to see what its reading and writing capabilities are. InfoTool had no problems detecting the DX-20A4PU's maximum reading and writing speeds, recording modes, buffer underrun protection and 2MB buffer.

InfoTool also shows that the DX-20A4PU is an RPC-2 DVD drive. This means that the drive's region is stored in the firmware. The region can be changed five times and after that it cannot be changed anymore. While there isn't an RPC-1 firmware available for the drive, there is a utility available that can make the drive region free.

While InfoTool gives us a quick glance at the DX-20A4PU's features, DVDINFOpro provides a little more information on some of the drive's reading and writing capabilities. By looking at the screenshot above you can see that while Lite-On's new drive can read and write to DVD+R DL, DVD-R DL and DVD-RAM media, it does not support the Mt. Rainier format.

The DX-20A4PU also supports a feature called "bitsetting." Using CD Speed, you can set the book type forDVD+R, DVD+RW and DVD+R DL media. Take note that the settings are all linked together so when you set the book type for one media type, it is applied to all.

Lite-On has once again turned to Nero for their software bundle. The CD that comes with the DX-20A4PU contains the Nero 7 Essentials suite which consists of Nero Express, Nero Vision, Nero Recode, Nero ShowTime and InCD.

Nero Express 7 - With Nero Express, Nero has taken the features and performance people have come to expect from Nero Burning Rom and combined them with a user friendly interface. Redesigned to maximize ease-of-use, Nero Express gives users the ability to quickly and easily burn audio, data and video to CD or DVD.

The version of Nero Express that Lite-On included with their new DVD±RW drive is 7.5.13.1. You can download the latest version of the software from Nero's website.

Nero Vision 4 - Nero Vision 4 is the latest version of Nero's video authoring application. Thanks to a user friendly interface, Nero Vision makes it easy for users to capture, edit and then burn their favorite videos to VCD, SVCD or DVD or export it to Nero Digital format.

Nero Vision also lets users add things like transitions, custom backgrounds, animated menus and text effects. You can even use it to turn your photos into custom slide shows.

Nero Recode 2 - This program from Nero can copy unprotected DVD videos onto recordable DVD media. If the source disc is larger than 4.7GB, Nero Recode 2 has the ability to remove unwanted material and compress the contents so that it will fit onto a single blank DVD disc.

Nero Recode 2 will also let you convert your DVD movies to Nero Digital. Using Nero's own MPEG-4 audio and video encoder, an entire DVD movie can be compressed so that it will fit onto a CD. Better yet, Nero Recode 2 does this with little loss of quality.

 

Nero ShowTime 2 - Nero ShowTime is Nero's software DVD player. Along with support for DVD's, ShowTime can be used to play back VCD's, SVCD's and miniDVD's as well as any MPEG, AVI or Nero Digital files you might have on your hard drive.

InCD 5 - InCD is Nero's packet writing software. Like Roxio's Drag-to-Disc or Sonic's DLA, it allows a person to use their CD-RW or DVD±RW drive as a big floppy disk. The person can then drag and drop files onto a CD-RW or DVD±RW disc. Many people consider InCD to be one of the best packet writing tools because of its simplicity and performance.

With the DX-20A4PU, Lite-On has delivered one of their most feature packed drives to date. Their new external drive supports all major DVD formats and sports some pretty impressive specs. The DX-20A4PU is capable of 20x DVD±R, 8x DVD±R DL, 8x DVD+RW, 6x DVD-RW and 12x DVD-RAM writing speeds and a maximum DVD read speed of 16x. Along with support for EZ-DUB, the drive also includes many of the features we've come to expect from Lite-On as well as more advanced ones like SmartWrite and OverSpeed. With all this, it's easy to see why the Lite-On DX-20A4PU gets the full 10 points for its features.

Lite-On's new external DVD writer was very easy to install. Thanks to its USB 2.0 interface, the entire installation process took only a matter of minutes. With no jumpers to worry about, it was as simple as connecting the USB cable, plugging in the power cable, and powering the drive on. Once connected to our test computer, it took only a matter of seconds for plug and play to install the necessary drivers. After making sure that the drive was recognized correctly in the Device Manager, I was ready to start installing the software.

Software Installation:

As I mentioned earlier, the DX-20A4PU comes with a CD full of software from Nero and Lite-On. If you have autorun enabled on your computer, the menu pictured below will automatically come up when you insert the disc.

As you can see, this menu is pretty straight forward. To install the writing software, you will want to choose the "Nero7 Essentials" option. After that, you will be taken to the Nero installation menu.

By default the setup program for Nero 7 Essentials will install everything but InCD onto your computer. If you don't want to install the entire suite, select the custom installation. From here you can choose the components you want.

The CD also contains Lite-On's EZ-DUB software. As with Nero, the installation process is fairly straightforward. All you need to do is choose what language you want and select the destination folder. Once you reboot, you'll be ready to back up your data and copy existing discs.

The Documentation:

Most of the DX-20A4PU's documentation is located in the "User's Manual." Similar to the ones included with Lite-On's other drives, this manual covers a number of topics. It starts out by getting the user familiarized with their new DVD writer. The first section goes over the drive'ssupported formats, recording modes, and system requirements. The manual also spends a few pages going over the locations and the functions of the buttons and connectors located on the front and back of the drive.

From here, the manual jumps right into the physical installation of the DX-20A4PU. The instructions are pretty brief since there really isn't much to do other than plug in a few cables and turn the computer on. Nevertheless, Lite-On has provided a nice diagram showing how the drive should be hooked up. Last but not least, the manual finishes up with a few short sections on how to operate the DX-20A4U and troubleshoot any problems that might arise.

Lite-On's new DVD writer also comes with a "Quick User's Guide." This fold out guide includes instructions on how to hookup the drive and install the bundled software. While a little short on words, there are a number of diagrams showing what to do. The guide also takes the user step by step through the process of duplicating a disc and backing up their files using the drive's EZ-DUB technology.

In the end, installing the DX-20A4PU was very easy. I had no problems getting the drive or the software installed and working. If you do run into trouble, the documentation Lite-On has provided is more than sufficient. However, I would have liked to have seen a little more drive specific information. Even then, the installation gets a 9 out of a possible 10.

While CPU, memory, OS and other variables don't often make a huge difference, there are some nonetheless. We have a computer that is used only for testing hardware. We do this so all tests can be compared reliably.

Test System:

For DVD writers the performance tests are broken down into four sections: CD read, CD write, DVD read and DVD write tests. Each benchmark test has been run three times. The score given is an average of the three. DMA has been enabled in device manager for all IDE devices supporting it.

CD Read Tests: For the read performance section of the CD-ROM benchmarks, CD WinBench 99 and CD Speed are used to test read speeds, seek times and CPU usage. For DAE testing both CD Speed and CD DAE are used. CD Speed is used to give an overall DAE speed rating and CD DAE is used to give the track by track extraction speeds and to check the extracted tracks for errors the drive may have created.

CD Write Tests: To test the write speeds, Nero Burning Rom is used to write 700MB to our test media. Times are recorded. To test rewrite scores, Nero is used again to time how long it takes to write 400MB of random files and directories. Then Sonic's DLA is used to test packet writing speeds. The same files are copied and pasted in Windows Explorer and timed.

DVD Read Tests: For the read performance section of the DVD benchmarks CD Speed is used to test read speeds, seek times, and CPU usage.

DVD Write Tests: To test the DVD write speeds, Nero Burning Rom is used to write 4GB to our test media. Times are recorded. Then Sonic's DLA is used to test packet writing speeds. The same files are copied and pasted in Windows Explorer and timed.

CD Winbench 99 Scores:

The CD Winbench test is as close as we can get to testing every day usage. It fires off eight different applications using scripts. This tries to mimic the activities of a person loading these programs onto their own computer.

Lite-On's new DVD writer performed pretty well in our CD Winbench tests. While the DX-20A4PU's overall score wasn't as high as the Samsung's, it had a low access time and some fairly good transfer rates. It started reading at about 21.1x (3170 / 150) on the inside and reached a maximum speed of about 43.1x (6470 / 150) on the outside.

CD Speed v4.7.7.7 - Pressed CD:

For this test I used a pressed CD containing one Mode 1 data track. The disc is 74:38 in size and is full of data and directories.

	Lite-On DX-20A4PU	Samsung SH-S203N	Lite-On DH-20A3H	LG GSA-H55L
Transfer Speed Average: Start: End:	36.09x 21.25x 47.73x	35.96x 20.75x 47.55x	35.81x 20.82x 47.36x	35.57x 20.47x 47.04x
Seek Times Random: 1/3: Full:	96ms 111ms 167ms	102ms 105ms 177ms	98ms 110ms 184ms	103ms 104ms 174ms
CPU Usage 1x: 2x: 4x: 8x:	2% 3% 5% 9%	0% 1% 2% 4%	6% 1% 2% 4%	0% 1% 2% 4%

The DX-20A4PU didn't perform as well as I had expected when reading pressed CD's.While rated at 48x, Lite-On's new external drive came up a little short of this number in our tests. On a more positive note, the DX-20A4PU's seek times were very good.

CD Speed v4.7.7.7 - CD-R Media:

For this test I made a copy of our pressed test CD. I used 12x rated Memorex Gold 74 minute media for the tests.

The DX-20A4PU was a little faster when reading CD-R media.Thanks to this small speed boost, it had no problems reaching a maximum transfer speed of 48x in our tests.

Lite-On's external DVD writer had no problems recognizing our 99 minute CompUSA media. The DX-20A4PU read our test disc from start to finish, reaching a maximum transfer speed of 52.62x.

CD Speed v4.7.7.7 - CD-RW Media:

For this test I made a copy of a pressed test CD. I used some PNY 80 minute CD-RW media for the tests.

When reading CD-RW media, the DX-20A4PU's transfer speeds are limited to only 32x. While Lite-On's new writer had no problems reaching this speed in our tests, it was the slowest out of the four drives here.

CD DAE and CD Speed v4.7.7.7 (DAE) - Pressed CD:

For this test I used Pure Funk. The CD is almost exactly 74 minutes. This helps to squeeze the maximum performance out of the CD.

Exact Audio Copy can tell us a lot about a drive's capabilities. You can see from the screen shot that the Lite-On DX-20A4PUsupports accurate stream, caches audio data and has the ability to retrieve C2 error information from audio CD's.

CD Speed	Lite-On DX-20A4PU	Samsung SH-S203N	Lite-On DH-20A3H	LG GSA-H55L
Average: Start: End: DAE Quality: Accurate Stream:	36.44x 21.20x 48.16x 10 Yes	30.93x 17.76x 40.86x 10 Yes	30.30x 17.64x 40.03x 10 Yes	31.43x 18.12x 41.52x 10 Yes

The DX-20A4PU did very well in our DAE tests. With a maximum speed of 48.16x, the drive had no problems taking the top spot in our tests.

To get a better look at the quality of the extracted audio we use CD DAE. CD DAE is actually designed to be an audio ripping program. It converts the CD-DA on the CD to .wav files. We use it in our testing because it can also be used as a quick and easy way to test the quality. Where CD Speed tests the DAE as one large session, CD DAE extracts each CD track individually. It actually extracts each track twice and then compares them to check for any errors. Every error a drive creates could be a hiss or pop you would hear later in the audio tracks.

While the DX-20A4PU started out a little faster when extracting our test CD with CD DAE, its average and maximum speeds were slower than what we saw with CD Speed.

CD DAE and CD Speed v4.7.7.7 (DAE) - CD-R Media:

For this test I used a copy of the Pure Funk CD. It's burned onto the same Memorex Gold 74 minute media I used in the CD Speed tests.

The LH-20A1L was a little slower when ripping audio CD-R discs. While the drive still performed well, it wasn't able to reach 48x this time around. So how did it do in CD Speed's advanced DAE tests? Take a look below.

Lite-On's new external DVD writer completed CD Speed's advanced DAE tests with an average score of 34.34x. The drive had no problems passing all of the on-the-fly tests and did not create any errors. If you look at the advanced features, you can see that the DX-20A4PU was able to read the CD-Text, subchannel data and even the lead in and lead out sections of the CD.

To see how well Lite-On's DVD writer can read scratched and dirty discs, I used CD Speed's ScanDisc utility to see how many sectors were damaged or unreadable. This is a very rough, but good way to test the drive's error correcting abilities.

CD Speed - ScanDisc

The DX-20A4PU handled scratched discs surprisingly well. By looking at the screenshot, you can see that the drive considered only 44% of the CD to be "damaged". More importantly, none of the sectors on the disc were unreadable.

You can also get an idea of how well the drive can read scratched and dirty discs by using CD DAE. CD DAE will extract the audio tracks twice and then compare them. From this information we can see what the drive's average speed was and how many errors it generated.

The DX-20A4PUgave us some mixed results in this test. While the number of errors was very low, the scratches on the disc caused it to slow down considerably.

CD Write and ReWrite Tests - Nero Burning Rom 7.10.1.0 andDLA 5.20:

For this test I randomly generated 700MB of files and directories to test the time it takes the drive to write and close a CD. All of the files are between 1MB and 25MB in size and no more than 10 directories deep. All of the times below include not only the actual writing time, but the lead in and out times too. This gives a more realistic idea of how long it takes to write a CD.

The DX-20A4PU has a maximum CD writing speed of 48x. To reach this speed, it uses CAV, or Constant Angular Velocity. With Verbatim's 52x media, the drive started writing at about 21.86x and reached a maximum speed of 49.16x at the end of the session. This gave Lite-On's new DVD±RW an average writing speed of about 37.22x.

To test the drive's writing times, I wrote our test data to some Verbatimmedia rated at 52x. The results are below.

Lite-On's new drive did fairly well in our CD writing tests. Thanks to its 48x CD writing speed, the DX-20A4PU was able to write an entire 701MB CD in 2:40.

To test the drive's writing quality I used Lite-On IT's KProbe2. Written by Karr Wang, this utility can be used to test the number of C1 and C2 errors on a disc. For these tests I used a Lite-On LTR-52246S (firmware 6S0F) and read the discs at 32x.

FTI 52x

Imation 52x (MBI)

Taiyo Yuden 52x

The DX-20A4PU's writing quality was very good. By looking at the KProbe screenshots, you can see that the discs burned by the drive had a low number of C1 errors and there were no C2 errors at all.

For the rewriting tests I created 400MB of files on the hard drive and wrote them in DAO mode using Nero. To test the packet writing speeds I copied and pasted the same files off the hard drive onto a CD-RW disc using DLA from Sonic. Verbatim's 32x Ultra Speed CD-RW media was used for these tests.

While the DX-20A4PU uses CAV when writing to CD-R discs, it uses Z-CLV, or Zone CLV, when rewriting at 32x. By looking at the screenshot above, you can see that it uses a total of three "zones" to reach its maximum speed. The drive starts writing at 16x and jumps to 24x at about the 13 minute mark.The DX-20A4PU writes at this speed until about the 54 minute mark. When it reaches this point, its writing speed increases to 32x and stays there until the end of the session.

Lite-On's new DVD writer didn't do as well as some of the other drives in our rewriting tests. Due to its Z-CLV writing method, the DX-20A4PU took 2:30 to write 400MB with Nero and 2:40 to do the same with DLA.

The DX-20A4PU also erases at 32x. While it didn't have the fastest quick erase time out of the four drives here, it was able to do a full erase in a respectable 3:36.

Nero CD Speed v4.7.7.7 - DVD-ROM:

For this test I used a single layer, single sided data DVD-ROM disc that is 4.37GB in size.

The DX-20A4PU performed very well when reading single layer DVD-ROM's. In our tests it started reading at 6.55x and reached a maximum transfer speed of 16.25x.Looking at the other scores, you can see that the drive's seek times were also quite good.

Nero CD Speed v4.7.7.7 - DVD-R, DVD-RW and DVD-RAM:

First, we'll look at the drive's DVD-R and DVD-RW reading performance. For this I made copies of our DVD-ROM test disc using some general use 4x DVD-R and 2x DVD-RW media from Verbatim and then ran our usual DVD read tests with CD Speed. For the DVD-RAM tests, media from Maxell was used. The results are below.

Verbatim DVD-R DL

The DX-20A4PU had no problems reading DVD-R, DVD-RW and DVD-R DL media. In our tests, the drive read DVD-R discs at 16x, and both DVD-RW and DVD-R DL media at a respectable 12x.

Maxell 12x DVD-RAM

Lite-On's new drive has a maximum transfer speed of 12x when reading DVD-RAM discs. By looking at the screenshot you can see that it starts reading at 5.93x and accelerates, reaching 12x at the 2.8GB mark.

Nero CD Speed v4.7.7.7 - DVD+R and DVD+RW:

Next we'll look at the drive's DVD+R and DVD+RW reading performance. For this I made a copy of our DVD-ROM test disc using some 4x DVD+R and 2.4x DVD+RW media from Verbatim. I then ran our usual DVD read tests with CD Speed. The results are below.

Verbatim DVD+R DL

The DX-20A4PU's performance was very similar to what we saw with DVD-R, DVD-RW and DVD-R DL media.The drive read DVD+R discs at 16x and both DVD+RW and DVD+R DL media at 12x.

Nero CD Speed v4.7.7.7 - DVD-Video:

For these tests I am using the US version of Transformers: The Movie on DVD. The disc is over 4GB and single sided.

The DX-20A4PU didn't slow down very much when reading single layer DVD videos. It started out at about 6.65x and reached a maximum read speed of 16.09x. Lite-On's new drive was also fairly quick when reading dual layer discs. By looking at the screenshot below, you can see that the drive's transfer speeds peaked at about 12x.

To see how well the DX-20A4PU worked as a DVD player, I watched a few scenes from Transformers: The Movie and Star Wars: The Phantom Menace using Nero Showtime. The drive had no problems playing back these movies with either program and was fairly quiet.

DVD Write and ReWrite Tests - Nero Burning Rom 7.10.1.0 andDLA 5.20:

To test the DVD writing performance of Lite-On's new drive I used Taiyo Yuden 16x DVD+R, Taiyo Yuden 16x DVD-R, Verbatim 8x DVD+RW and Verbatim 6x DVD-RW media. To get the writing times, a 4.38GB image was burned to our test discs using Nero.

While Lite-On claims that the DX-20A4PU can write to DVD+R and DVD-R media at 20x, the drive never reached that speed in our tests. For whatever reason, it limited the writing speed to only 18x. I tried various things, including disabling SMART-BURN and it had no effect.

Lite-On's new drive also features 8x DVD+RW and 6x DVD-RW writing speeds. In both cases it uses Z-CLV to reach its maximum writing speed.

The DX-20A4PU didn't perform as well as the other drives when writing to DVD+R and DVD-R media. With its writing speed limited to 18x, it took nearly 5 and a half minutes to burn an entire 4.7GB DVD. Unfortunately, due to its Z-CLV writing method, the DX-20A4PU also lagged behind the other drives when writing to DVD+RW and DVD-RW media.

To check the media compatibility of the DX-20A4PU, I ran a few tests using some of the media available in my area. The media types, along with the average time it took the drive to write our 4.38GB image, are listed below.For these tests, SmartWrite and OverSpeed were left disabled.

So what about writing quality? Thanks to KProbe, we can test a disc's PI (Parity Inner) and PIF (Parity Inner Fail) rates.For these tests I used a Lite-On SHM-165H6S (firmware HS0E) and read the discs at 4x with the PI and PIF ECC sums set to 8 and 1 respectively. For comparison, I also tested the discs on a BenQ DW1640. When combined with Nero CD Speed, the DW1640 is able to report PI Errors, PI Failures, Parity Outer Failures and even jitter levels. For this test, the discs are read at 8x with both the PI and PIF ECC sums set to 8.

So what are "good" results supposed to look like? With KProbe, the PI errors should not exceed 280 and the number of PIF errors should stay below 4. When testing with CD Speed, the number of PI errors should stay below 280 as well. However, because it scans with an ECC sum of 8, a higher number of PIF errors is acceptable, as long as they do not exceed 32. Since POF errors are uncorrectable, we really don't want to see any of them at all.

I also put these discs through a "stress test" by reading them back at 16x with the DW1640. By reading these discs back at this speed, we can see if there are any readability issues caused by the number of errors or high levels of jitter.

The DX-20A4PU's writing quality was pretty good with most of the DVD+R media we tested. Aside from a few small spikes, the PI/PIF rates stayed well within acceptable limits.

Lastly, here are some results from our DVD-R test media. While the writing quality varied from one manufacturer to another, the results were pretty good for the most part.

To test the DX-20A4PU's packet writing performance I used DLA 5.20. Verbatim 8x DVD+RW, Verbatim 6x DVD-RW and Maxell 12x DVD-RAM media were used once again.

To test the DX-20A4PU's packet writing performance I used DLA 5.20. Verbatim 8x DVD+RW, Verbatim 6x DVD-RW and Maxell 12x DVD-RAM media were used once again.

The DX-20A4PU had no problems holding its own when reading and writing to DVD-RAM media. However, due to its Z-CLV writing method, it wasn't as fast asthe other drives when writing to DVD+RW and DVD-RW discs.

Double Layer DVD Write Tests - Nero Burning Rom 7.10.1.0:

To test the double layer DVD writing performance of the DX-20A4PU, I used DVD+R DL and DVD-R DL media from Memorex, Philips, RiDATA and Verbatim. I created about 8GB of random files and directories on my hard drive and then burned them to our test discs with Nero.

While no match for the drives from Samsung and LG, the DX-20A4PU took a respectable 17:54 to write 8001MB of data. So what about writing quality? Take a look below.

The writing quality was pretty good with Philips' 8x and Verbatim's 2.4x DVD+R DL media. Aside from a few isolated spikes, the PI/PIF rates stayed within acceptable limits. Unfortunately, the results weren't as good with the 8x DVD+R DL media from Memorex and Verbatim. When scanned with the BenQ DW1640, the error and jitter rates were very high at the layer change.

The DX-20A4PU performed relatively well when writing to DVD-R DL media. Thanks to its 8x writing speed, the drive took less than 19 minutes to write 8001MB of data. So what about writing quality? Take a look below.

While the writing quality was fairly good with Verbatim's 4x DVD-R DL media, their new 8x rated discs yielded some mixed results. The error rates stayed within acceptable limits when tested with KProbe. However, when scanned by the DW1640, the error and jitter rates were higher than we'd like to see. The worst results were with RiDATA's 4x DVD-R DL media. Looking at the CD Speed screenshot, you can see that the PI/PIF rates were pretty high throughout the entire disc.

Performance Revisited:

When it comes down to it, the performance of Lite-On's new "EZ-DUB" drive was hit and miss. The DX-20A4PU did not perform as well as expected when writing DVD's. It failed to write to DVD±R discs at 20x and lagged behind the other drives when writing to DVD±RW and DVD±R DL media. On the other hand, the DX-20A4PU was fairly quick when reading DVD's. In our tests, it was able to read single layer DVD's at 16x and both DVD±R and DVD±RW media at a respectable 12x.

The DX-20A4PU also did relatively well in our CD read tests. The drive read pressed and CD-R discs at speeds as high as 48x and had some very good seek times. When it came to writing CD's, Lite-On's new drive gave us some mixed results. While the DX-20A4PU turned in some very impressive times when writing to CD-R media, its Z-CLV writing method put it at a slight disadvantage in our rewriting tests. With all things considered, the Lite-On DX-20A4PU gets a 5 out of 10 for the performance section of this review.

Over the last year or so, we've had a number of Lite-On's DVD writers in the 'Labs. Offering a good mix of value, performance and features, these drives are very popular among both consumers and enthusiasts. Needless to say, I had high expectations for the DX-20A4PU. While an improvement in many ways over Lite-On's previous EZ-DUB drives, its performance came up short in a number of key areas.

According to Lite-On, the DX-20A4PU can write to DVD-R and DVD+R media at 20x. While this looks impressive on paper, the drive reached a maximum writing speed of only 18x in our tests. As a result, it took nearly five and a half minutes to write an entire 4.7GB DVD. The DX-20A4PU didn't have any problems writing to DVD±RW, DVD±R DL and DVD-RAM media. However, its Z-CLV writing method did put it at a slight disadvantage when writing to DVD+RW and DVD-RW discs.

When it came to media compatibility, the DX-20A4PU gave us some mixed results. While the drive wrote toall of our test media at its rated speeds or better, only two types were recognized as being capable of 20x writing speeds. On the other hand, the DX-20A4PU's writing quality was fairly good, at least with most single layer DVD±R discs. With DVD±R DL media though, there were a number of cases where the PI/PIF rates were higher than we'd like to see. Hopefully, Lite-On can address this in a future firmware update.

Lite-On's new external drive did very well in our DVD read tests. It was able to read single layer DVD-ROM's and DVD-Videos at 16x and had some very good seek times. The DX-20A4PU also reached some pretty impressive transfer speeds with other types of DVD media. In our tests, it read DVD±R discs at 16x and DVD±RW, DVD±R DL and DVD-RAM media at an impressive 12x.

Reading CD's wasn't a problem for the DX-20A4PU either. In our tests, the drive read pressed and CD-R media at speeds as high as 48x and CD-RW discs at 33x. This level of performance carried over to our DAE tests, where the drive ripped audio CD's at an impressive 48x. When it came to writing CD's, the DX-20A4PU performed as expected. The drive had no problems holding its own when writing to CD-R media. However, itsZ-CLV writing method put it at a slight disadvantage in our rewriting tests.

When it comes to features, the DX-20A4PU definitely delivers. Along with old favorites like SMART-BURN and SMART-X, it supports two of Lite-On's more advanced technologies, SmartWrite and OverSpeed. The drive also has a good number of writing and rewriting speeds to choose from and has the ability to set the book type of DVD+R/RW and DVD+R DL media. Most notable though, is the DX-20A4PU's EZ-DUB technology. By following a few simple steps, users can quickly and easily duplicate a disc or backup their data.

While the DX-20A4PU has its rough spots, it has a lot of potential. If Lite-On can improve the media support and get the drive to write at 20x, it could be one of the better external DVD writers out there. The DX-20A4PU is available now and can be purchased through the vendors listed on Pricegrabber for less than $60.

Highs:

• Supports Lite-On's EZ-DUB technology
• Writes to DVD-R and DVD+R media at 20x
• Writes to DVD+RW media at 8x
• Writes to DVD-RW media at 6x
• Writes to DVD+R DL and DVD-R DL media at 8x
• Reads and writes DVD-RAM media at 12x
• Reads single layer DVD-ROM's at 16x
• Reads DVD±R media at 16x
• Reads DVD±RW and DVD±R DL media at 12x
• Features 48x CD-R and 32x CD-RW writing speeds
• Good selection of writing and rewriting speeds
• Excellent DAE speeds
• Low seek times
• Supports SMART-BURN, SMART-X, ABS, SmartWrite and OverSpeed technologies
• Supports bitsetting for DVD+R/RW and DVD+R DL media
• Includes software from Nero
• Supports 99 minute CD-R media
• Nice looking design

Lows:

• Failed to write to any DVD±R media at 20x
• Questionable writing quality with some DVD±R DL media
• Slower than other drives when writing to DVD±RW media
• Reads CD-RW media at only 32x