To be "truly" nomadic, the linux should boot from external medium, lets say (but not limited to) from CDROM /DVDROM, USB-stick, HDD-external, PXE + network). Plus at destination to have the appropriate interfaces to boot that storage (PATA/SATA/SCSI/Firewire/USB).
In this post I limit (myself) to physical CD / DVD connected by PATA or USB. For USB theoretical maxim speed I wrote previously.
I try to "demonstrate" that a bus like ATA/33 (33 MB/s) is enough for a CD or DVD, because the limited maxim theoretical speed for CD or DVD.
PATA (Parallel Advanced Technology Attachment) interfaces, commonly known as IDE (Integrated Drive Electronics):
Common Standards: ATA/33, ATA/66, ATA/100, and ATA/133. Speed range from 33 MB/s up to 133 MB/s
PS: Significantly slower than SATA, which ranges [150 - 969] MB/s
Extra info for SATA (Serial Advanced Technology Attachment)
SATA I (1.5 Gbps): 150 MB/s maximum theoretical speed
SATA II (3 Gbps): 300 MB/s maximum theoretical speed.
SATA III (6 Gbps): 600 MB/s maximum theoretical speed. (Typical SSDs operate around 500–550 MB/s.)
CD-ROM (compact disc read-only memory)
KB/s Mbit/s MB/s RPM (at edge) Equivalent
1× 150 1.2288 0.146 200–530
2× 300 2.4576 0.293 400–1,060
4× 600 4.9152 0.586 800–2,120
8× 1,200 9.8304 1.17 1,600–4,240
10× 1,500 12.2880 1.46 2,000–5,300 UBS 1.0/1.1 (12 Mbit/s)
12× 1,800 14.7456 1.76 2,400–6,360
20× 1,200–3,000 < 24.5760 < 2.93 4,000 (CAV)
24× 1,440–3,600 < 29.4910 < 3.51 4,800 (CAV)
32× 1,920–4,800 < 39.3216 < 4.69 6,400 (CAV) USB 2.0 (480 Mbit/s)
36× 2,160–5,400 < 44.2368 < 5.27 7,200 (CAV)
40× 2,400–6,000 < 49.1520 < 5.86 8,000 (CAV)
48× 2,880–7,200 < 58.9824 < 7.03 9,600 (CAV)
52× 3,120–7,800 < 63.8976 < 7.62 10,400 (CAV) ...undesirable noise (disk vibration, rushing air, spindle motor)
56× 3,360–8,400 < 68.8128 < 8.20 11,200 (CAV)
72× 6,750–10,800 < 88.4736 < 10.50 2,700 (multi-beam) << far from USB 3.0 (5 Gbit/s)!!
DVD (Digital video/Versatile Disk)
Mbit/s MB/s RPM (constant linear velocity) Equivalent-CDROM Equvialent-USB
1× 11 1.38 1400 (inner) 580 (outer) cdrom-10x (max. 1.46 MB/s) USB 1.0/1.1 (12 Mbit/s)
2× 22 2.8 2800 (inner) 1160 (outer) cdrom-20x (max. 2.93 MB/s)
2.4× 27 3.3 3360 (inner) 1392 (outer)
2.6× 29 3.6 3640 (inner) 1508 (outer) cdrom-24x (max. 3.51 MB/s)
3× 33 4.1 4200 (inner) 2320 (outer)
4× 44 5.5 5600 (inner) 2900 (outer) cdrom-36x (max. 5.27 MB/s) USB 2.0 (480 Mbit/s) !!
6× 67 8.3 8400 (inner) 3480 (outer)
8× 89 11.1 4640 (CAV; no longer uses CLV) cdrom-72x (max.10 MB/s)
10× 111 13.9 5800
12× 133 16.6 6960
16× 177 22.2 9280 limit reading speed to 16× (constant angular velocity)
18× 199 24.9 10440
20× 222 27.7 11600
22× 244 30.5 12760
24× 266 33.2 13920 PATA/33 (33 MB/s)
extra (unsolicited) info:
CD-ROM (compact disc read-only memory), in Mode1 format: raw sector =2,352 bytes (16 bytes header + 2,048 bytes DATA +288 bytes CRC).
- "1× speed CD". = 153.6 kB/s (150 KiB/s). Size CDROM = 650 MB
- "1× speed DVD" = 1,385 kB/s (1,353 KiB/s); Size DVD=4.7GB =aprox. 6x CDROM.
If the disc spins at a constant angular velocity (CAV), the linear velocity is 2.4 times higher at the outer edge.
(temporary) Summary:
- max. CD-72x (ha, ha, very few) is equivalent speed to a DVD-8x suitable for PATA/33 , or USB 3.0
- CD-36x is equivalent speed to a DVD-4x suitable for PATA/33, or UBS 3.0 (practicaly USB 2.0, YMMV)
- max. CD-32x is suitable for PATA/33, or USB 2.0A max. CD-10x is equivalent speed to a DVD-1x suitable for PATA/33, or USB 1.1
[Edit]: Corrected typo. Changed 40 Mbit/s to 480 Mbit/s, two places. Rich