What's in the box?:

  • Plextor PX-Q840U 20x DVD±RW/RAM Drive
  • Plextor Software Disc
  • Quick Installation Guide
  • Roxio Venue Quick Install Guide
  • USB 2.0 Cable
  • AC Power Adapter
  • 2 RiDATA Qflix DVDs
  • Drive Stand
  • CinemaNow $25 Gift Certificate
  • Warranty Information

Physical Features:

The drive Plextor sent us for this review was manufactured in November of 2008 and had firmware 1.05. For this review we used firmware versions 1.05 and 1.08.

From the front, the PX-Q840U looks nothing like its internal counterpart, the PX-806SA. Plextor's new external DVD writer sports a more sophisticated look thanks in part to its glossy plastic and chrome highlights. The PX-806SA also has its share of logos. Along with the large "Plextor" and "PX-Q840U" logos, you can see a few showing support for the DVD Multi and DVD+ReWritable specifications, as well as Sonic's Qflix technology.

The PX-Q840U's enclosure is radically different from Plextor's previous external drives. Relatively compact for an external DVD writer, it measures only 163 x 51.5 x 224.7 mm (6.42 x 2.03 x 8.85 in) and weighs in at 1.1 kg (2.43 lbs). Like the front bezel, the enclosure is made out of glossy black plastic. While this looks nice, finger prints and smudges have a tendency to stand out.

In case you missed the fact that PX-Q840U is capable of writing to Qflix media, there is an extra large Qflix logo on top of the drive. On the bottom, the drive has four small rubber feet to keep it from sliding around when placed on a flat surface. The PX-Q840U can also be positioned vertically using the included drive stand.

The rear of Plextor'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 Plextor's website and the documentation that came along with the drive.

   Plextor PX-Q840U 20x DVD±RW/RAM
DVD+R Write Speeds 20x, 18x, 16x (CAV)
12x, 8x (P-CAV)
6x, 4x (CLV)
DVD+RW Write Speeds 8x, 6x (Z-CLV)
4x, 2.4x (CLV)
DVD-R Write Speeds 20x, 18x, 16x (CAV)
12x, 8x, (P-CAV)
6x, 4x (CLV)
DVD-RW Write Speeds 6x (Z-CLV)
4x, 2x (CLV)
DVD+R DL Write Speeds 8x, 6x (Z-CLV)
4x, 2.4x (CLV)
DVD-R DL Write Speeds 8x, 6x (Z-CLV)
4x, 2x (CLV)
DVD-RAM Write Speeds 12x, 8x (P-CAV)
6x, 5x, 3x, 2x (CLV)
CD Write Speeds 48x (CAV)
40x, 32x, 24x (P-CAV)
16x, 8x (CLV)
CD Rewrite Speeds 32x, 24x (Z-CLV)
16x, 10x, 4x (CLV)
DVD Read Speeds 16x Max (DVD-ROM Single Layer)
12x Max (DVD-ROM Dual Layer)
16x Max (DVD±R)
12x Max (DVD±RW)
12x Max (DVD±R DL)
12x Max (DVD-RAM)
CD Read Speeds 48x Max (CD-ROM/CD-R)
40x Max (CD-RW)
DAE Speed 48x Max
Buffer Size 2 MB
Random Access Times
160 ms (CD)
170 ms (DVD)
230 ms (DVD-RAM)
CD Formats CD-DA
CD-ROM
CD-ROM XA
Video CD
Photo CD
CD-Text
CD-I (FMV)
CD-Extra
Multi-Session
CD-R
CD-RW
DVD Formats DVD-ROM
DVD-R/RW
DVD+R/RW
DVD+R DL
DVD-R DL
DVD-RAM
CD Recording Modes Track At Once
Session At Once
Disc At Once
Fixed And Variable Packet Writing
DVD+R and DVD+R DL Recording Modes Incremental Recording
DVD+RW Recording Mode Random Access Write
DVD-R Recording Modes Disc At Once
Incremental Recording
DVD-RW Recording Modes Disc At Once
Restricted Overwrite
Incremental Recording
Sequential Recording
DVD-R DL Recording Modes Disc At Once
Incremental Recording
Layer Jump Recording
DVD-RAM Recording Mode Random Access Write

More Features:

By looking at the picture below, you can see that Plextor's new external DVD writer is identified as a "PLEXTOR DVDR PX-Q840U."

Nero shows that the PX-Q840U has a maximum CD writing speed of 48x and a 2048KB buffer. This buffer is backed up by Sanyo's BURN-Proof buffer underrun protection. Technically this isn't true, as the drive uses a chipset from MediaTek, not Sanyo. According to Nero, the PX-Q840U 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 PX-Q840U 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 PX-Q840U's maximum reading and writing speeds, recording modes, buffer underrun protection and 2MB buffer.

InfoTool also shows that the PX-Q840U 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 PX-Q840U'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 Plextor's new drive can read and write to most DVD formats and offers support for Qflix and DVD Download recording.

Oddly enough, the PX-Q840U does not support bitsetting. I tried a number of programs, including Nero and CD Speed, and none of them let me change the book type of DVD+R, DVD+RW or DVD+R DL media. After running a few tests, I found that the PX-Q840U does not automatically set the book type either. According to Plextor, this feature was supposed to make it onto the drive and did not for whatever reason. The company currently plans to add it in a future firmware update.