| Capacity | |||
|---|---|---|---|
| Parameter | Units | DVD | CD |
| max payload | GBytes | 4.7 (12 cm SL) 8.54 (12 cm DL) 1.46 (8 cm SL) 2.66 (8 cm DL) | 0.742 (
mode 2) 0.650 (mode 1) |
| Data rates | |||
|---|---|---|---|
| channel rate | mbit/sec | 26.16 | 4.3218 |
| FEC rate | mbit/sec | 3.00 | 0.4704 |
| user rate | mbit/sec | 11.08 | 1.47 |
| actual data rate | mbit/sec | 10.08 | 1.4112 |
| Pits and tracks | |||
|---|---|---|---|
| pit width | micron | 0.5??? | 0.5 |
| track pitch | micron | 0.74 | 1.6 |
| Min pit length | micron | 0.40 (SL) 0.44 (DL) | 0.833 to 0.972 |
| Max pit length | micron | 1.87 (SL) 2.13 (DL) | 3.054 to 3.560 |
| min pit length | - | 2T | 2T |
| max pit length | - | 10T | 10T |
(Note: the minimum pit length for each layer of the Double layer disc is 10% greater than single layer disc. Hence the 10% less dense figure for Dual layer discs.)
| Data format | |||
|---|---|---|---|
| sector size | bytes | 2048 | 2352 (mode 2) 2048(mode 1) |
| Movement | |||
|---|---|---|---|
| Spiral direction | clockwise | clockwise | |
| max revolutions/sec | Hz | 25.5 (12 cm disc) | 8 (12 cm disc) |
| min revolutions/sec | Hz | 10.5 | 3.5 |
| Reference scanning velocity | m/s | 3.49 (SL) 3.84 (DL) | 1.2 to 1.4 |
| Optics | |||
|---|---|---|---|
| wavelength | nm | 650 or 635 | 790 |
| Numerical Aperture of Objective Lens | - | 0.60 | 0.45 |
| refractive index | - | 1.55 | 1.55 |
| Spot Size (lambda/NA) | - | 0.63 | 1 |
| Focus Depth (Focus Margin, lambda/NA^2) | - | 0.47 | 1 |
| Chromatic Aberration (Title margin, lambda/NA^3) | - | 0.35 | 1 |
| Spherical Aberration (Thickness Tolerance, lambda/NA^4) | - | 0.26 | 1 |
| Reflectivity | % | 70 minimum (SL) 25 to 40 (DL) | 70 minimum |
| Mass | |||
|---|---|---|---|
| Thickness of substrate | mm | 0.6 | 1.2 |
| disc thickness | mm | 1.2 | 1.2 |
| disc mass | grams | 13 to 20 (12 cm) 6 to 9 ( 8 cm) | 14 |
| Thickness of spacing layer in Dual Layer | micron | 40 to 70 | N/A |
| FEC | |||
|---|---|---|---|
| Error correction | method | RS product code | CIRC |
| FEC consumption | % | 13 | 25 |
| FEC format | bytes | (208,192,17)x(182,172,11) | (28/32)x(24/28) |
| Sector constraint length | - | 16 (=32 Kbytes) | 1 |
| correctable burst length | mm | 6.0 (SL) 6.5 (DL) | 2.5 |
| Channel code | |||
|---|---|---|---|
| Channel modulation | method | 8/16 (EFM+) | 8/14 + 3 merge bits |
| Run length | bits | (2,10) | (3,11) |
| Diameters | |||
|---|---|---|---|
| outer | mm | 120 (12 cm) 80 (8 cm) | 120 |
| outer lead in | mm | 117 (12 cm) 78 (8 cm) | 117 |
| outer data | mm | 116 (12 cm) 76 (8 cm) | 116 |
| inner data | mm | 48 (12 cm) 48 (8 cm) | 50 |
| inner lead in | mm | 45 (12 cm) 45 (8 cm) | 46 |
| center hole | mm | 15 (12 cm) 15 (8 cm) | 15 |
