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When Spun Really Fast, CDs Explode
Anonymous Coward writes: "Ever wonder why cd-rom/cd-rw drives are not getting any faster? Wonder why they heat up? This page has a rather amusing experiment where they put various CD's into something that can spin up to 30,000RPM and found that most cd's explode at just around 28,000RPM. Oh and they seem to like using Corel CD-ROM discs for their experiment." Update: Yep, it's a dupe...
This story (with the same URL) was posted here. I know duplicate-URL checking wouldn't help everything, but it could at least catch stuff like this...
PenguiNet: the (shareware) Windows SSH client
the "x" rating is not how many times faster it spins... its how many times faster it transfers data... some crappy 50x drives really do spin at 50x faster but the better ones have 2 or 4 heads to they really run at 25x the speed or 13x the speed(for 52x)... this is why u go for asus or toshiba or some good name brand company when you get a cdrom... bad position of holes makes it so my crappy 50x cdrom really can only read 3/4 of the discs...
dvds are the same thing... a 1x dvd player is enough to stream the dvd onto a tv but a 8x/16x or whatever is better for ripping... a 8x dvd reader will actually transfer many times faster than an 8x cdrom becuase of the dvd format in which more data is read at the same time...
unzip; strip; touch; finger; mount; fsck; more; yes; unmount; sleep
Is it so hard to post the link? Or is HTML too difficult for you?
A 64x CAV CD-ROM drive will spin at a maximum of 12,800 RPM, according to my math, but drives don't seem to exist at that speed just yet. More common 56x drives spin at 11,200 RPM.
If things are consistantly and violently exploding at a little over twice that speed, would it not make sense that there is a very real safety issue in making things faster than this?
One might theorize that off-balance discs, cracked/scored/otherwise-damaged media, and just plain bad luck might cause things to go dangerously amiss even at current speeds.
Current high-end SCSI hard drives spin at 15,000RPM, but do so using extremely well-balanced, carefully-produced, expensive solid aluminum platters and motors. And, besides, they're also encased in heavy metal boxes, and don't have a soft plastic face through which to fire shrapnel into the chest of the user.
Consider that a CD-ROM has a much larger diameter than a typical hard disk platter, and is thus exposed to far greater centrifugal force and linear velocity. Consider also that a CD-ROM drive only costs a few dollars to make, and that CDs are down to a couple of cents each in large volume.
Given this information and that contained in the article, I doubt it would take much effort to make a CD explode in a current 56x drive, thus presenting a very real bottleneck, indeed.
Kid-proof tablet..
Zen Research has developed a technology that reads the disk using 7 beams in parallel, achieving high throughput without spinning the disk at ridiculous speeds.
It has been licensed by several companies including Kenwood that used it to produce an amazing 72x drive.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
The old-style Aluminum-shell SCBA air tanks (used as an oxygen supply for firefighters) are only about 1mm thick...and they routinely carry air at a pressure of 22,000 psi.
Those plastic fragments were able to crack open 1mm thick aluminum shielding! That means that the pressure those fragments applied was well in excess of 22,000 psi! Yikes!
What's this Submit thingy do?