CD Speed 99 - Pressed CD
CD Speed 99 was also used to test the drives' ability to read a data disc. The same three discs (pressed CD, CD-R, CD-RW) from the file copy test were used in the following tests. First, the pressed CD:

Plextor 12/10/32A reading pressed disc

The CD Speed tests are always interesting because they show how modern CAV drives actually work. CAV drives have a range of speeds, depending on whether the data is being read from the inside or outside of the disc. Transfer rates start low at the inside of the disc and peak at the outside of the disc. Marketing being what it is, the peak speed is the speed at which the drive is typically rated. CD Speed shows the true story, which is that a drive will rarely hit its advertised speed in real-world use.

The 12X Plextor presents a classic CAV curve on the pressed disc, steadily climbing in speed as it works its way to the outside of the disc. By the end of the disc it's actually peaking at slightly higher than its rated 32X, topping out at 33.07X, with an average speed of 25.14X.

Plextor 16/10/40A reading pressed disc

The 16X Plextor displays a similar curve, but it starts higher and has a greater slope. Like its 12X cousin, the 16X Plextor winds up scoring slightly higher than its 40X rating, and turns in an impressive average of 31.38X. Interestingly, however, the 16X drive's access times are notably higher (worse) than the 12X drive. Additionally, the 16X drive was somewhat inconsistent on this test. In one trial, it exhibited a dropoff in performance at the end of the disc, similar to that of the Samsung below.

Samsung 52X reading pressed disc

For whatever reason, the Samsung did not do very well with the pressed CD. Obviously things started out OK, but soured by the end. This may explain why the Samsung failed to win by a larger margin in the file copy test, though in both that test and this one, its average speed is higher than either of the Plextor drives, and access times are very impressive.