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Disc rotation speeds, RPM, sectors per second.

General discussion about recordable CD, DVD and BD media and write quality testing.

Disc rotation speeds, RPM, sectors per second.

Postby TL7 on Fri Nov 17, 2017 5:36 am

SOURCE: my post on VideoHelp. Also posting on MyCe. http://forum.videohelp.com/threads/3858 ... -second%29

Hello.
What I know is that the same rotation speed of a disc allows ×2.4 for 12cm (×1.6 for 8cm diameter) faster data reading at the outer edge.

Because I am extremely knowledge thirsty and inquisitive, I thought that the community on VideoHelp can help me with my endless knowledge hunger. I keep a list of many questions I will maybe ask and topics (for example: calculating lossless digital zoom and loss value)

I would like to know the relationships of the following parameters of CD, DVD, HD-DVD and BD (and HVD?).
Rotation speed at CAV (unchanging rotation speed) ×1 or ×1.6 or ×2.4 = how many rotations per minute (RPM) or per second?
×1 CLV (same reading speed, varying rotation speed) speed = How many sectors per second?
Are the values slightly different for DVD+, DVD-, DVD-DL and DVD-RAM?
Is 1× on a CD 150 or 176.4 KiB/s? [2352×(1500/1764)=2000!].

This can also be useful for calculating the rotation speed acoustically.
SCSi is partially crippled. The PC only knows the disc rotation speed by the data rate, not by the disc drive rotation engine.

I hope that the community can provide useful information, and I would appreciate it.
TL7
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Re: Disc rotation speeds, RPM, sectors per second.

Postby Ian on Mon Nov 20, 2017 3:37 pm

I can answer the data rate for 1x pretty easily. I'm going to borrow this nice graphic from Wikipedia.

https://en.wikipedia.org/wiki/CD_and_DVD_writing_speed

write speeds.PNG
write speeds.PNG (16.65 KiB) Viewed 246 times


And RPM's for CD's

https://en.wikipedia.org/wiki/CD-ROM

cdrom rpm.PNG
cdrom rpm.PNG (85.33 KiB) Viewed 246 times
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Re: Disc rotation speeds, RPM, sectors per second.

Postby Ian on Mon Nov 20, 2017 3:49 pm

If we're to compare that to say a DVD, it spins about 3 times faster (edit.. its actually 570rpm.. so not quite 3x) than a CD at 1x. With its greater data rate, its equivalent to a CD being read at about 9x. With DVD's spinning about 3x faster, this also explains why we don't see any DVD drives faster than 18x since it would spin about as fast as a 54x CD-ROM.

(Again.. thank you Wikipedia) https://en.wikipedia.org/wiki/DVD_recor ... s_and_DVDs

dvd rpm.PNG
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Re: Disc rotation speeds, RPM, sectors per second.

Postby Ian on Mon Nov 20, 2017 3:54 pm

And then you have Blu-ray, which has a data rate of 36 Mbit/s at 1x. I'm not sure what the RPMs are though. Anyone know? I've come across references saying that a drive spins at 10,000 RPM at 12x, but nothing for 1x.

https://en.wikipedia.org/wiki/Blu-ray_Disc_recordable

bluray data rate.PNG
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