52x CDRW Roundup - Page 10

Writing Quality Tests - Page 1

We used Taiyo Yuden 80min 48x CD-R media and burned the same AudioCD project (with CD-Text) at all the available recording speeds with the Premium drive. Below you can see the 3T Pit & Land Jitter graphs.

- 3T Pit results

As we can see from the top graph, the 3T Pit Jitter for the 8x,16x and 20x writing speeds. Writing at 24x gave the highest jitter after the 25min of the disc, and the maximum value reached the 40nsec by the 42min address.

Writing at 32x did not gave any high jitter values. In the 40x writing jitter became higher after the 70min address, where the writing speed reached the 40x. The 52x disc gave the highest average jitter. However, the maximum value is not very high, and as you can see in the graph (black line). The jitter drops to lower levels by the end of the disc, which means that the drive reduced the writing speed and did not finish writing at 52x. This is also confirmed by the duration of the writing process with the specific disc.

- 3T Land results

The average 3T Land results are increased over those in the previous measurements of the 3T Pit Jitter. Again the drive gave higher jitter at 24x. The highest jitter value was reported with the 40x disc, and reached the 44nsec. Below you can see all the average 3T Pit and Land jitter values for the supported recording speeds.

Recording Speed	3T Pit Jitter (ns)	3T Land Jitter (ns)	> 35ns	Max value (ns)
8X	26.56	30.66	No	28 Pit, 32 Land
16X	27.17	30.59	No	31 Pit, 33 Land
20x	29.29	32.41	No	32 Pit, 32 Land
24x	34.95	36.17	Yes	41 Pit, 40 Land
32x	30.12	34.12	Yes	33 Pit, 37 Land
40x	32.80	37.41	Yes	41 Pit, 44 Land
52x	34.37	37.39	Yes	40 Pit, 42 Land

Generally, the performance of Plextor Premium is adequate for all the writing speeds. The highest jitter was reported at the 24x, 40x and 52x writing speeds. However, these values were not very high and probably will not produce errors.

- PlexTools Professional Jitter Tests

In order to have a second idea of the jitter results we measured the same discs with the PlexTools Professional software.

• Plextor 48X CD-R@52X

We used Plextor 48X CD-R media and burned the same amount of data in all the available writing speeds. You can see all the jitter graphs in the following links:

• 40X recording speed
• 32X recording speed
• 24X recording speed
• 20X recording speed
• 16X recording speed

As we have mentioned, the Plextools graphs show the an average relative jitter values over the 3T~11T range, showing the general Jitter trend. Thus, the graphs we make with hardware equipment cannot absolutely match to those coming from PlexTools. After all, our graphs measure only 3T Pit & Land measurements and not 11T.

• Mitsubishi Chemicals 24X US-RW@24X

We burned a MC 24X US-RW media at 24X (P-CAV) Below is the Jitter/Beta graph according to PlexTools.

The graph shows that jitter is lower in the beginning of the disc, where the writing speed is lower (24X P-CAV), and it is gradually increased by the end of the disc. Since the vertical axes do not give absolute values, we cannot make out if the level of the reported jitter values. The Beta graph (red line) is horizontal and this probably indicates acceptable readability of the disc.

We measured the same disc with our hardware equipment, and you can see the graph below:

It seems that the US-RW media produces high 3T Land values, after the 30min of the disc. This value reaches the 44nsec by the end of the disc. The 3T Pit value is low for all the disc area.

- PlexTools Professional C1 and C2 Tests

We measured the recorded discs with the C1/C2 Plextools test. Below you can see the C1/C2 scan with Plextor 48X CD-R media @ 52X (4X CLV reading speed).

Plextor 48X CD-R	C1			C2			CU
Recording Speed	Avg / Sec	Max / Sec	Total	Avg / Sec	Max / Sec	Total	Avg / Sec	Max / Sec	Total
52x	0.4	10.0	2161.0	0.0	27.0	27.0	0.0
40x	0.5	11.0	2204.0	0.0	0.0	0.0	0.0

Plextools measurements did not show any problems at the highest supported writing speeds. The 52X speed gave some C2 errors but no CU (uncorrectable) errors occurred.

• Mitsubishi Chemicals 24X US-RW

After checking the MC 24X US-RW disc no C2 or CU errors were reported.