The Plextor 755UF data transfer modes, for both read and write operations, are what we would expect to find on any internally mounted IDE based drive. The theoretical maximum transfer speed for a USB 2.0 based device is 40 Megabytes per second. Given that the highest transfer rate of the Plextor 755UF is 22.16 Megabytes per second, at a 16X DVD read speed,  there will be plenty of bandwidth on the USB 2.0 bus to support this drive. On a more technical note, you also have to take into account that the drive is a going to be using Constant Angular Velocity - so the higher transfer rates will only be seen on the outer edges of a disk. In short - the target media would have to be filled to near maximum capacity to reach the maximum transfer speed advertised.

     Testing......

     To test the read speed, I used the tool Speed CD by Nero on a couple of factory pressed game discs. #1 is a DVD  from Flight Simulator X and #2 is a CD from the game Company of Hero's. This should test both DVD-ROM and CD-ROM reading capabilities quite nicely. Further read tests will be conducted using burned media in the form of a benchmark DVD+R,  DVD-R, and CD-R that I made especially for testing optical drives. Each disk has been filled to near-maximum capacity with files of varied sizes and depth in the directory tree.

     For comparison, the benchmark disks were created on a totally separate DVD recorder to ensure that neither drive was given preferential treatment. Not that this a 'shoot-out' between drives and interfaces, but the results of the Plextor 755UF will be compared to that of an internal IDE Lite-On SHM-165H6S. For all tests, the Plextor drive will be attached using the USB 2.0 bus only.

Silver Press DVD
Flight Simulator Deluxe DVD #1

 PLEXTOR 755UF read results

Lite-On SHM-165H6S read results

     A quick comparison of the DVD reading results show almost a mirror image of each other. Even if you're new to the Nero CD-DVD Speed tool, the graphical charts are very easy to understand. The speed diagram on the left is marked with 3 lines. Two horizontal lines -- Green showing the data transfer rate,  and yellow representing the rotational speed of the disc. The red vertical line at the very end shows the amount of data on the disc. The text boxes on the right break down the test at various points in the read process. The fairly straight yellow line shows that the rotational speed did not vary (much) while the green data transfer line continues to gain the further from the middle the optical pickup is moved. This confirms the Type of read as Constant Angular Veloticy, or CAV as displayed in the TYPE block.

     The Plextor met its random access time of 150ms with ease and actually had a lower CPU utilization rate at 8x transfer speeds, than its IDE counterpart. That could also be the host controller the Lite-On is connected to is the J-Micron controller which has been added by Asus to the P5B-WiFi deluxe motherboard. Why Intel chose to exclude native support for IDE devices is beyond me. There simply are not enough SATA optical drives on the market yet, unless this is the first move in a hopeful push for a major market shift.....

Silver Press CD
Company of Hero's CD- #2

 PLEXTOR 755UF read results
SPEED READ DISABLED

 PLEXTOR 755UF read results
SPEED READ ENABLED

Lite-On SHM-165H6S read results

     In order for the Plextor 755UF to reach its full potential when reading a Compact Disc, the PlexTools Pro software must be installed and a Drive Setting called SpeedRead must be enabled. Folks who have used Plextor drives before are probably already familiar with this. Plextor uses this as a method to reduce excessive vibration. Interesting enough, enabling SpeedRead dramatically increased our random seek time.

     The Plextor 755UF still shows very small CPU utilization throughout the entire range of the disc read operation. With a full disc, this is exactly what we want. It shows that very little effort is required to read the disc which leaves more CPU cycles to actually instal the software.