Plextor PX-740UF 16x FireWire/USB 2.0 DVD±RW

Model: Plextor PX-740UF 16x FireWire/USB 2.0 DVD±RW
Manufacturer: Plextor
Provided By: Plextor America

As one of the biggest names in the storage industry, Plextor doesn't need much of an introduction. Considered by many to be the professional's choice, their drives are known the world over for the performance, quality and features they offer. To keep ahead of the competition, Plextor has continued to lead the way, bringing cutting edge technologies to market. Today, their product lineup includes a number of high performance CD and DVD writers, many with features found nowhere else.

Last fall we took a look at Plextor's low cost 16x DVD±RW, the PX-740A. While lacking many of Plextor's advanced technologies, the PX-740A delivered impressive performance at an affordable price. Sticking to this same formula, Plextor introduced a new external DVD writer, the PX-740UF. Sporting the same specs as its internal counterpart, the PX-740UF is capable of 16x DVD±R, 8x DVD+RW, 6x DVD-RW, 8x DVD+R DL and 4x DVD-R DL writing speeds and a maximum DVD read speed of 16x. On top of that, the drive features 48x CD reading and writing speeds, 32x rewriting speeds, and support for both FireWire and USB 2.0.

With specs like this, the PX-740UF has the potential to be one of the fastest external DVD writers currently available. To give you an idea of what to expect, we'll take a look at some of its features and then see how it compares to some of the 16x DVD±RW drives from the competition. Does Plextor's external DVD writer have what it takes? Keep reading as we find out.

What's in the box?:

• Plextor PX-740UF 16x DVD±RW Drive
• Quick Installation Guide
• Plextor DVD Writing Software - Revision 13.01
• USB 2.0 Cable
• AC Power Adapter
• Emergency Eject Tool

Physical Features:

The drive Plextor sent us for this review was manufactured in August of 2005 and had firmware version 1.01. It was also manufactured in China and had a TLA# of "0001". For this review we used firmware versions 1.01 and 1.02.

By looking at the front of the PX-740UF you can see that it is based on Plextor's internal 16x DVD±RW, the PX-740A. The two drives not only share the same bezel design, but many of the same logos. Below the tray you can see a few showing off its support for DVD+R DL, DVD+ReWritable, DVD-R/RW and Ultra Speed CD-RW media.

Measuring 6.58" x 2.09" x 9.98" (167.1mm x 53.0mm x 253.5mm) and weighing in at 3.52 lbs (1.6 Kgs), the PX-740UF is not the most compact or lightweight external drive we've tested. Nevertheless, the case is constructed of a durable black plastic that should stand up well to everyday use.

If you look closely, you can see that there is another LED on the top of the PX-740A. This LED lights up a bright blue when the drive is powered on. On each corner of the drive is a rubber strip. This strip not only keeps the PX-740A planted on your desk, it lets you position it either horizontally or vertically.

The rear of Plextor's new external writer also has its share of connectors. Starting from the left, you can see the PX-740A's FireWire ports, interface switch, USB 2.0 connector, on/off switch and power connector. I was a little surprised to see that the drive had a cooling fan, especially considering its power supply is located outside of the case in a small "power brick."

Technical Specs:

Most of the specs below have been taken from Plextor's website and the manual that came with the drive.

More Features:

By looking at the picture below, you can see that Plextor's external DVD writer is identified as a "PLEXTOR DVDR PX-740A."

The Nero screenshot also shows that the PX-740UF has a maximum CD writing speed of 48x and a 2048KB buffer. This buffer is also backed up by Sanyo's BURN-Proof buffer underrun protection. Technically, this isn't true as the drive uses a chipset from Philips, not Sanyo. According to Nero, the drive 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.

Like the BenQ DW1640, the PX-740UF can do EFM encoding correctly. Using CloneCD version 4.2.0.2 with AWS disabled, Iwas able to reproduce older SafeDisc 2 protected titles like Max Payne along with some of the newer ones protected by SafeDisc 2.51 like Serious Sam: The Second Encounter.

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 PX-740UF's maximum reading and writing speeds, recording modes, buffer underrun protection and 2MB buffer.

InfoTool also shows that the PX-740UF is an RPC-2 DVD drive. This means that the drive's region is stored in the firmware. The drive's region can be changed five times and after that it cannot be changed anymore. A patched RPC-1 firmware can be downloaded here. Just keep in mind that it is not supported by Plextor nor by CDRLabs. Use it at your own risk.

While InfoTool gives us a quick glance at the PX-740UF'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 Plextor's new drive can read and write to both DVD+R DL and DVD-R DL media, it does not support the Mt. Rainier format.

The PX-740UF also supports a feature called "bitsetting." While the drive automatically sets the book type of DVD+R DL media to "DVD-ROM", you can manually do the same with single layer DVD+R and DVD+RW media using CD Speed. This feature comes in handy if you have an older DVD player that has problems playing recordable media.

For the PX-740UF's software bundle, Plextor America has turned to Nero. The CD that comes with the drive contains copies of Nero Express 6, NeroVision Express 3, Nero ShowTime, Nero Recode 2, InCD, BackItUp and PhotoShow Express.

Nero Express 6 - 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. While the interface has been simplified, Nero Express still supports more advanced features like VCD and DVD creation, CD/DVD duplication, overburning, CD-Text and realtime audio filters

The version of Nero Express that Plextor included with their new DVD±RW drive is 6.6.0.14. You can download the latest version of the software from Nero's website.

NeroVision Express 3 - NeroVision Express 3 is the latest version of Nero's video authoring application. Using a user friendly interface very similar to that of Nero Express, NeroVision Express 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.

NeroVision Express 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 new 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 without any loss of quality.

Nero BackItUp - If you're looking for a way to quickly and easily backup your data, Nero BackItUp is the answer. This new program from Ahead Software lets you backup your data to CD/DVD, hard disc, image recorderor another computer on your LAN.

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 or AVI files you might have on your hard drive.

Nero Media Player - Nero Media Player features on-the-fly encoding of audio CD's to MP3, HE-AAC, TwinVQ, WMA, and WAV format.The MP3 encoder uses the latest audio codec technology from Fraunhofer.While most of the plugins are unrestricted, the MP3 encoder included with this version of the program is limited to only 30 audio tracks.If you need to encode more you will probably want to upgrade to Nero's NeroMIX.

InCD 4 - 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 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.

PhotoShow Express - Plextor's new drive also comes with Nero's all in one photo suite, PhotoShow Express. This software can do a number of things including edit and touch up your photos and organize them into various albums. PhotoShow can even be used to create musical slideshows. These slideshows can then be burned to disc or published to the web.

Plextor's new external DVD writer definitely isn't short on features. Like the BenQ drive it's based on, the PX-740UF sports some pretty impressive specs. The drive is capable of 16x DVD±R, 8x DVD+RW, 6x DVD-RW, 8x DVD+R DL and 4x DVD-R DL writing speeds and a maximum DVD read speed of 16x. Along with support for both USB 2.0 and FireWire, the PX-740UF also incorporates a number of useful features like buffer underrun protection and bitsetting. Last but not least, Plextor tops all of this off with an impressive software bundle from Nero. With all this, it's easy to see why the PX-740UF gets a 9 out of 10 for its features.

Plextor's new external DVD writer was very easy to install. Thanks to its support for both USB 2.0 and FireWire, the entire installation process took only a matter of minutes. With no jumpers to worry about, it was as simple as connecting the USB (or FireWire) 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 PX-740UF comes with a CD full of software from Nero. If you have autorun enabled on your computer, the menu shown 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 "Nero 6 and Express Suite" option. After that, you will be taken to the Nero installation menu.

By now most of you should be pretty familiar with this menu. From here you can install Nero, NeroVision Express 3, Nero Media Player, Nero PhotoShow Express or InCD 4. You can install each component individually, or everything but InCD and PhotoShow Express in one shot. Once you reboot, you'll be ready to start burning your own discs.

Documentation:

To make the PX-740UF as affordable as possible, Plextor has tried to cut costs in a few areas. One example of this is the documentation. Instead of large printed manual, most of the drive's documentation is located on the software CD in electronic format. Similar to the ones included with Plextor's other DVD writers, the manual starts out by getting the user familiarized with their new DVD writer. The first section goes over the drive's capabilities, features and system requirements.

From here, the manual jumps right into the physical installation of the PX-740UF. 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. Even then, Plextor has provided a nice diagram showing how the drive should be hooked up. The manual continues on by going over the basic operation of the PX-740UF. Along with information on how to use and maintain the drive, there is a short list of frequently asked questions. Last but not least, you have a list of specifications and recommended media.

The PX-740UF also comes with a "Quick Reference Guide." This small, fold out guide takes the user step by step through the installation process. While a little short on words, Plextor has provided a few diagrams showing how the drive should be hooked up. For most people, the "Quick Start Guide" will be all they'll need to get the PX-740UF up and running.

Installing Plextor's external DVD writer couldn't be easier. Thanks to its FireWire and USB 2.0 interface, it's as simple as plugging in a few cables and flipping a switch. Nevertheless, if you do run into trouble, the documentation Plextor has provided is quite good, even though it is in electronic format. Overall, I give the installation a solid 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 v3.0 and CD Speed v4.10 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 650MB and 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 v4.10 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.

Plextor's external DVD writerdid pretty well in the CD Winbench portion of our tests. While the PX-740UF's overall score wasn't as high as some of the other drives, it had some very good transfer rates. The drive started reading at 19.6x (2945 / 150) and reached a maximum speed of about 43.6x (6540 / 150) on the outside.

CD Speed v4.10 - 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.

	Plextor PX-740UF	NEC ND-4550A	LG GSA-4167B	Sony DRU-810A
Transfer Speed Average: Start: End:	36.48x 20.67x 48.27x	35.60x 20.54x 47.09x	35.63x 20.45x 47.28x	36.39x 20.64x 48.13x
Seek Times Random: 1/3: Full:	98ms 114ms 167ms	137ms 145ms 219ms	114ms 126ms 183ms	106ms 123ms 176ms
CPU Usage 1x: 2x: 4x: 8x:	1% 2% 4% 7%	17% 1% 3% 6%	1% 1% 3% 36%	1% 1% 3% 6%

The PX-740UF performed very well when reading pressed CD's. It flew through CD Speed's transfer rate tests, reaching a maximum read speed of 48.27x. Looking at the other scores, you can see that the drive's seek times were also quite good.

CD Speed v4.10 - 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.

Like the other drives, the PX-740UF was a little faster when reading CD-R media. Thanks to this small speed boost, the drive was able to reach a maximum transfer speed of more than 49x. On top of that, its seek times were again quite good.

Plextor's external DVD writer had no problems recognizing our 99 minute CompUSA media. The drive read our test disc from start to finish, reaching a maximum transfer speed of 53.14x! This is pretty good for a drive rated at only 48x.

CD Speed v4.10 - 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.

While the PX-740UF can read pressed and CD-R media at 48x, its CD-RW read speeds are limited to only 40x. As you can see, the drive had no problems reaching this speed in our tests.

CD DAE and CD Speed v4.10 - 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 while the Plextor PX-740UF supports accurate stream and has the ability to cache audio data, it does not have the ability to retrieve C2 error information.

CD Speed	Plextor PX-740UF	NEC ND-4550A	LG GSA-4167B	Sony DRU-810A
Average: Start: End: DAE Quality: Accurate Stream:	36.84x 20.94x 48.70x 10 Yes	30.94x 17.99x 40.12x 10 Yes	30.81x 17.50x 40.79x 10 Yes	36.76x 20.90x 48.59x 10 Yes

The PX-740UF did very well in our DAE tests. With a maximum speed of 48.70, it 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 Plextor's new DVD writer 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 v4.10 - 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.

While the PX-740UF was a little slower when extracting audio from CD-R media, this didn't keep it from reaching amaximum DAE speed of 48x. So how did it do in CD Speed's advanced DAE tests? Take a look below.

Plextor's external DVD writer completed CD Speed's advanced DAE tests with an average score of 34.87x. The drive had no problems passing all of the on-the-fly tests and did not create any errors. In the advanced tests, the PX-740UF was able to read the CD-Text, subchannel data and lead in section of the CD, but for whatever reason was not able to read the lead out.

To see how well Plextor's new drive 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

While all of that green looks good, these ScanDisc results are a little misleading. Without the ability to retrieve error information, the PX-740UF is unable to determine which sectors are damaged or 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 PX-740UF gave 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 6.6.0.16 andDLA 4.95:

For this test I randomly generated 650MB and 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 PX-740UF has a maximum CD writing speed of 48x. To reach this speed, it uses CAV, or Constant Angular Velocity. With Fuji's 48x media, the drive started writing at about 21.26x and reached a maximum speed of 48.00x at the end of the session. This gave the PX-740UF an average writing speed of about 36.28x.

To test the drive's writing times, I wrote our test data to some Taiyo Yuden manufactured Fuji media rated at 48x. The results are below.

Plextor's new external DVD writer did fairly well in our tests. While no match for the DRU-810A, the PX-740UF took less than 3 minutes to write an entire 650MB CD.

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.

Fuji 48x (Taiyo Yuden)

Memorex 52x (CMC)

Verbatim 52x

The PX-740UF's writing quality is 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.

The PX-740UF uses P-CAV, or Partial CAV, when rewriting at 32x. By looking at the screenshot above, you can see that the drive starts rewriting at about 21.31x and accelerates, reaching its maximum speed at about the 22 minute mark.

Plextor's new DVD writer did very well in our rewriting tests.Thanks to its P-CAV writing method, the PX-740UF took only 2:10 to write 400MB with Nero and 1:53 to do the same with DLA.

The PX-740UF also erases at 32x. It not only had the best quick erase time out of the four drives here, it was able to do a full erase in an impressive 3:45.

Nero CD Speed v4.10 - DVD-ROM:

A little editorial note here. Like a CD-ROM, you will get different benchmark results depending on what kind of discs you are using. You are probably going to get varying results from a full data disc to a single layer movie disc. You're also going to get different results for single and dual layer discs.

The CD Speed website recommends using a single layer DVD-ROM disc with a capacity of at least 4GB. If you use a dual layer disc you probably won't get the best results because most DVD-ROM drives slow down to read them. Some even slow down to read single layer DVD-Video discs. To make a long story short, I am using a 4.37GB single layer, single sided disc for this test.

The PX-740UF wasn't as fast as I had expected when reading single layer DVD-ROM's. While the drive started out fairly quick, it had a hard time reaching its rated speed in our tests. Nevertheless, its seek times were very good.

Nero CD Speed v4.10 - DVD-R and DVD-RW:

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. The results are below.

Unfortunately, the PX-740UF came up short of its rated speed once again - this time with DVD-R media. Looking at the scores above, you can see that it reached a maximum transfer speed of only 14x.

Verbatim DVD-R DL

Plextor's new DVD writer had no problems reading Verbatim's 4x DVD-R DL media. The PX-740UF started reading at 5.02x and reached a maximum transfer speed of 12.10x.

Nero CD Speed v4.10 - 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.

The PX-740UF's performance with DVD+R and DVD+RW media was very similar to what we saw with DVD-R and DVD-RW media. The drive read DVD+R discs at 14x and DVD+RW media at 12x.

Verbatim DVD+R DL

Reading Verbatim's double layer DVD+R media wasn't an issue for the PX-740UF either. With a maximum transfer speed of 12.11x, it had no problems taking the top spot in CD Speed's transfer rate tests.

Nero CD Speed v4.10 - 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 PX-740UF didn't slow down very much when reading single layer DVD videos. It started out at about 6.51x and reached a maximum read speed of 15.01x. Plextor's new drive was also surprisingly fast when reading dual layer discs. By looking at the screenshot below, you can see that the drive's transfer speeds peaked at an impressive 12.07x.

To see how well the PX-740UF worked as a DVD player, I watched a few scenes from Transformers: The Movie and Star Wars: The Phantom Menace using WinDVD 4 and PowerDVD 5. The drive had no problems playing back these movies with either program and was fairly quiet.

DVD Write and ReWrite Tests - Nero Burning Rom 6.6.0.16 andDLA 4.95:

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

When writing to DVD+R and DVD-R media at 16x, the PX-740UF uses CAV. By looking at the screenshots above, you can see that the drive starts writing at about 5.6x and accelerates, reaching its maximum speed as it reaches the end of the disc.

The PX-740UF also features 8x DVD+RW and 6x DVD-RW writing speeds. While the drive uses CLV when writing to DVD-RW media, it uses Z-CLV to reach its maximum DVD+RW writing speed.

Plextor's new drive performed pretty well in our DVD writing tests. While not nearly as fast as the drive from LG, it turned in some respectable times with both DVD±R and DVD±RW media.

While Plextor has a list of recommended media on their website, I wanted to see for myself how well the PX-740UF worked with some of the DVD+R and DVD-R media currently available. The media types, along with the average time it took the drive to write our 4.38GB image, are listed below.

So what about writing quality? Testing a drive's DVD writing quality isn't easy. Until now, there were very few options, unless you wanted to shell out thousands of dollars for a certified test machine. 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 SOHW-1673S (firmware JS07) 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 PX-740UF'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 within acceptable limits. The only real exception being Optodisc's 16x DVD+R media. When scanned with the BenQ DW1640, the PI/PIF rates jumped up considerably near the end.

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. The only exception was Daxon's 16x media. When tested with CD Speed, there were a number of POF errors on these discs.

To test the PX-740UF's packet writing performance I used DLA 4.95. Verbatim 8x DVD+RW and 6x DVD-RW media were used once again.

The PX-740UF performed pretty well in our packet writing tests. While not as fast as some of the other drives when writing our test data to disc, it took a little more than 6 minutes to read back all 4GB of files and directories.

Double Layer DVD Write Tests - Nero Burning Rom 6.6.0.16:

To test the double layer DVD writing performance of the PX-740UF, I used Verbatim 8x DVD+R DL, Verbatim 2.4x DVD+R DL, Memorex 2.4x DVD+R DL and Verbatim 4x DVD-R DL media. I created about 8GB of random files and directories on my hard drive and then burned them to our test discs with Nero.

The PX-740UF had no problems writing to Verbatim's 8x and 2.4x DVD+R DL media at 8x. Unfortunately, Memorex's Ritek manufactured discs would not work at anything faster than 2.4x.

The PX-740UF did very well in this test. Thanks to its 8x DVD+R DL writing speed, the drive took less than 15 minutes to write 8001MB of data. So what about writing quality? Take a look below.

The writing quality was very good with Verbatim's 8x DVD+R DL media. As you can see, the PI/PIF rates remained very low from start to finish. The results weren't as good with the 2.4x DVD+R DL media from Verbatim and Memorex. However, the PI/PIF rates remained within acceptable limits.

As you can see, the PI/PIF rates remained very low from start to finish. Unfortunately, the results weren't as good with the 2.4x DVD+R DL media. The PI/PIF rates were not only higher, there were a number of POF errors on the discs from Verbatim.

The PX-740UF also features 4x DVD-R DL writing speeds. To test the drive's writing times, Verbatim's 4x DVD-R DL media was used.

The PX-740UF wasn't nearly as fast when writing to DVD-R DL media. In our tests, it trailed behind the drive from NEC by more than 8 minutes. So what about writing quality? Take a look below.

The PX-740UF's writing quality was pretty good with Verbatim's 4x DVD-R DL media. The PI/PIF rates stayed within acceptable limits when tested with both KProbe and CD Speed and there were no readability problems.

Performance Revisited:

Before I wrap up this section of the review, I wanted to point out that the PX-740UF didn't work as advertised with some USB or FireWire controllers. As you saw in our tests, the drive was not able to read at 16x when connected to the USB 2.0 ports on our ASUS K8V SE Deluxe (VIA K8T800) motherboard. Switching to an Intel based motherboard really didn't help either. When connected to an MSI 875P Neo-FISR (Intel 875P), the drive was lucky to reach even 14x. I also ran a few tests using the FireWire connector on the ASUS K8V SE Deluxe. While the PX-740UF was able to read at 16x, its writing speed peaked at only 13x.

The PX-740UF still performed pretty well throughout most of our tests. While not as fast as some of the other drives when writing to DVD-R DL discs, it turned in very good times with DVD±R, DVD±RW and DVD+R DL media. The PX-740UF was also fairly quick when reading DVD's. In our tests, it was able to read single layer DVD-ROM's and DVD±R discs at speeds has high as 15x and other types of recordable media at 12x.

Plextor's external writer also did very well in our CD read tests. It had no problems reading all types of media at its rated speeds and had some very good seek times. Writing CD's wasn't a problem for the PX-740UF either. The drive turned in some impressive times and its writing quality was quite good. With all things considered, the Plextor PX-740UF gets a solid 8 out of 10 for the performance section of this review.

The PX-740UF is a lot like its internal counterpart, the PX-740A. Designed with the cost conscious consumer in mind, this stylish, BenQ DW1640 based drive delivers impressive performance without all the bells and whistles found on Plextor's PX-716 series of drives.

Like its BenQ counterpart, the PX-740UF can write to both DVD+R and DVD-R media at 16x. At this speed, it took the drive about 6 minutes to burn an entire 4.7GB DVD. Plextor's external DVD writer also did pretty well in our rewriting tests, turning in some very good times with both DVD-RW and DVD+RW media. Even more impressive was the PX-740UF's DVD+R DL writing performance. Thanks to its 8x writing speed, the drive took less than 15 minutes to burn an entire 8.5GB DVD. Unfortunately, its 4x DVD-R DL writing speed also put it at a slight disadvantage in some of our tests.

When it came to media compatibility, Plextor's external writer gave us some mixed results. While the drive wrote tomost of our test media at its rated speed, it would not write to any 8x DVD±R media at 16x. On the other hand, the PX-740UF's writing quality was, for the most part, pretty good. However, there's still room for improvement, especially with Optodisc's 16x DVD+R and Daxon's 16x DVD-R media. Hopefully Plextor can tweak this in a future firmware update.

The PX-740UF also performed relatively well in our DVD read tests. While it came up a little short of its rated speeds, the drive was able to read single layer data and video DVD-ROM's at speeds as high as 15x and had some pretty good seek times. The PX-740UF also performed pretty well with other types of media. In our tests, it read DVD±R discs at 15x and both DVD±RW and DVD±R DL media at an impressive 12x.

Reading and writing CD's wasn't a problem for the PX-740UF either. In our tests, the drive had no problems reading pressed and CD-R media at 48x and CD-RW discs at 40x. The drive also did well in our DAE tests, reaching speeds as high as 48x. This level of performance carried over to our writing and rewriting tests. The PX-740UF turned in some impressive times thanks to its 48x CD-R and 32x CD-RW writing speeds and its writing quality was quite good.

As I mentioned before, the biggest difference between the PX-740UF and Plextor's previous DVD writers is the number of features. While the drive offers things like buffer underrun protection, bitsetting and support for both USB 2.0 and FireWire, it lacks many of Plextor's more advanced technologies like Q-Check, GigaRec and Autostrategy. The PX-740UF doesn't come with a lot of extras either. To keep costs down, the manual is on the CD and instead of Roxio's Easy Media Creator, the drive comes bundled with the Nero 6 suite.

The PX-740UF is available now and can be purchased through some of the online vendors listed on Pricegrabber. Prices vary depending on the seller, but Plextor's new external DVD writer can be picked up for around $150.

Highs:

• Writes to DVD±R media at 16x
• Writes to DVD+RW media at 8x
• Writes to DVD-RW at 6x
• Writes to DVD+R DL media at 8x
• Writes to DVD-R DL media at 4x
• 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
• Very good transfer speeds with all types of CD media
• Excellent DAE speeds
• Good CD writing quality
• Includes buffer underrun prevention technology
• Supports 99 minute media
• Good selection of writing and rewriting speeds
• Includes software from Nero
• Supports bitsetting for DVD+R/RW and DVD+R DL media
• Good documentation

Lows:

• Does not perform to spec with all FireWire/USB chipsets
• Cannot write to 8x DVD±R media at 16x
• Cannot do write quality testing
• Has a 2048KB buffer
• Does not include a FireWire cable
• Still expensive