I know that 1x = 150kb/s, but why does it equal that specific amount¿
150kb/s is about the speed that audio CDs are read at. The first CD-ROM drives read only at the standard audio CD speed, so when drives that read data twice as fast arrived, they were naturally called 2x, and the “x” designation has been with us ever since.
Incidentally, when you’re dealing with modern CD-ROM drives, the “x” rating is usually either an out-and-out fabrication or true only under such special conditions that it’s nearly meaningless. Confronted with the choice between a 48x and a 50x drive, for example, it’s really impossible to say which will be faster in actual use without actually testing them.
I have a 48x drive at work, and a 32x drive at home, but the drive at home is much faster in practice.
Because when you’re playing an audio CD, it has to pump out data at a rate of 150kb/s*. So a 2X CD-ROM is twice as fast as an audio CD player.
*Actually, 44,100 samples/sec * 2 channels * 2 bytes / sample = 176.4 kb/s, but roughly speaking…
150 kilobits per second was the original data transfer rate of CD drives. (And still the rate for audio-only CD players …?) Hence the baseline, hence 1x (one times).
Later, you saw faster drives that could read a 300 kbps. They called them 2x (two times the original speed).
Now that we’re up to 24x or so as a defacto baseline for new CD drives, you hardly see anyone mention the speed. But CD burners are still slow, and you now see THEM rated at 1x, 2x, 4x, etc., speeds.
CD Burners arent slow…
My 40x 12x 48x (Read, Write, Rewrite i believe) will burn you a full CD in under 3 minutes.
Thats write, rewrite, read.
The problem with the X rating for reading/writing is the fact that the cd isn’t spinning that fast most of the time. It may hit 48x read, but averages 20x whilst a quality 32x might average 28x. In this case the 32x would obviously be faster. Still it’s a good general indicator.
Whups, I forgot to mention that moc.liamtoh@rorrim Mentioned the speeds in an unusual order. Generally the fastest speed is read, 2nd fastest is write and slowest is rewrite.
In my experience, CD-RW drive speeds are normally listed in write/rewrite/read fashion. I remember about two years ago it was more common to see read/write/rewrite (I recall purchasing a Sony 32x8x4x drive), but nowadays the former is more common (I purchased a Lite-On 48x24x48x CD-RW drive this christmas).
I stand corrected, then. My drive is 2 or 3 years old, and runs via USB, not firewire, etc. It can write at 2X speed, but at 4X speed, the USB bottleneck becomes too great and usually results in disaster.
I hope I’m not alone in having always read it as “four times”, “sixteen times” etc. It’s a multiplication sign, not a letter x, right? As in, two times as fast (as standard audio speed), etc.
I say “four speed”. Maybe I’m the only one.
Yes, it is a multiplication sign.
Despite this, everyone I know (myself included) says “four ecks,” “sixteen ecks,” etc, at least when speaking aloud. This isn’t, perhaps, the most correct way to get what you’re after, but it’s probably the best way to get the apathetic high-school kid at Circuit Central to help you find what you’re looking for.