The test
A quick calculation gives us the burn times for the drive - 20 minutes for a full 700MB. Definitely not up to the current internal CD-RW speeds, but this is not marketed as a high output drive. Rather it is intended for those who need maximum portability, ease of use, and who can wait 20 minutes to burn a CD.
|
Recording
Speeds and Times
|
|
74
mins / 650 mb
|
1x
|
74 mins
|
|
74
mins / 650 mb
|
2x
|
37
mins
|
|
74 mins / 650 mb
|
4x
|
18.5 mins
|
|
74
mins / 650 mb
|
6x
|
12.34
mins
|
|
74
mins / 650 mb
|
8x
|
9.25 mins
|
|
74 mins / 650 mb
|
12x
|
6.17 mins
|
As far as operation goes, we experienced no difficulties whatsoever. We put around 50 CD's through the unit and came away with only 2 coasters. The first occured when we tried a game of Quake 3 while burning an ISO. The second a complete burn process failure while transferring images from a digital camera over the USB bus. Both times we were trying to see how hard we could stress the system before the USB bus was unable to keep up with the data requirements. Normal office tasks like web surfing, word processing, light image editing and MP3 playback caused no problems.
The unit is certainly adequate for most applications when being used as a normal CD drive. It does have a noticeably longer access time than an internal unit, but it's only noticeable when browsing a CD. Access times are quite good for an external USB unit and much better than we were expecting, putting up a 144ms random seek time. Because the USB bus limits transfer speeds to just over 1.4MB/sec reads are certainly slower that most are used to, but it gets the job done.
Transfer rates are just what they are advertised at, clocking in at just over 6.1X across the CD. This is due to the fact that the internal Mitsumi drive is actually rated at 24X read and the USB bus is limiting the transfer rates. A quick calculation of the maximum USB bandwidth (1,500KB/sec) divided by 150K/sec (1X) says that we should be able to move data across the bus at around 10X. So why is the speed limited to 6X? Well, LaCie took into account the fact that you might want to use other USB devices along with the CD drive, and pumping data onto the bus at its' maximum rate is very likely to cause problems. To us it seems that LaCie has been very conservative limiting the speed to 6X. Not many people are likely to be using another device simultaneously which requires 600KB/sec. Considering that the internal drive is capable of 24X, we would have liked to have seen 8X throughput.
Over on the right hand side you see a common downfall of USB devices. The CPU usage is well over 3 times that of its' internal IDE counterparts. (The 8X measurement is irrevelent because the drive cannot read at that speed.)
On the audio side of things, I'm not sure how many people would use this drive for DAE, but Digital Audio Extraction speeds were also much better than expected. Posting a solid 5X across the entire CD with no errors is very respectable.
Conclusion
