# what does the "x" stand for in cd players¿ **URL:** \ **Category:** Factual Questions\ **Created:** [March 10, 2003, 9:26pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412 "2003-03-10T21:26:53Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Mr\_Urt](https://avatars.discourse-cdn.com/v4/letter/m/8491ac/32.png) [@Mr\_Urt](https://boards.straightdope.com/u/Mr_Urt)\ **Post date:** [March 10, 2003, 9:26pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/1 "2003-03-10T21:26:53Z")
I know that 1x = 150kb/s, but why does it equal that specific amount¿ ---
**Author:** ![Lagged2Death](https://avatars.discourse-cdn.com/v4/letter/l/ac8455/32.png) [@Lagged2Death](https://boards.straightdope.com/u/Lagged2Death)\ **Post date:** [March 10, 2003, 9:38pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/2 "2003-03-10T21:38:43Z")
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. ---
**Author:** ![heresiarch](https://avatars.discourse-cdn.com/v4/letter/h/278dde/32.png) [@heresiarch](https://boards.straightdope.com/u/heresiarch)\ **Post date:** [March 10, 2003, 9:40pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/3 "2003-03-10T21:40:01Z")
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… ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [March 10, 2003, 9:46pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/4 "2003-03-10T21:46:17Z")
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. ---
**Author:** ![moc.liamtoh\_rorrim](https://avatars.discourse-cdn.com/v4/letter/m/f17d59/32.png) [@moc.liamtoh\_rorrim](https://boards.straightdope.com/u/moc.liamtoh_rorrim)\ **Post date:** [March 10, 2003, 11:14pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/5 "2003-03-10T23:14:31Z")
CD Burners arent slow… My 40x 12x 48x (Read, Write, Rewrite i believe) will burn you a full CD in under 3 minutes. ---
**Author:** ![Harmonix](https://avatars.discourse-cdn.com/v4/letter/h/3ec8ea/32.png) [@Harmonix](https://boards.straightdope.com/u/Harmonix)\ **Post date:** [March 11, 2003, 12:30am UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/6 "2003-03-11T00:30:44Z")
> [@](#): > > 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. ---
**Author:** ![Harmonix](https://avatars.discourse-cdn.com/v4/letter/h/3ec8ea/32.png) [@Harmonix](https://boards.straightdope.com/u/Harmonix)\ **Post date:** [March 11, 2003, 12:32am UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/7 "2003-03-11T00:32:08Z")
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. ---
**Author:** ![Alereon](https://avatars.discourse-cdn.com/v4/letter/a/ecd19e/32.png) [@Alereon](https://boards.straightdope.com/u/Alereon)\ **Post date:** [March 11, 2003, 1:16am UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/8 "2003-03-11T01:16:20Z")
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). ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [March 11, 2003, 7:34pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/9 "2003-03-11T19:34:56Z")
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. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [March 11, 2003, 10:06pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/10 "2003-03-11T22:06:35Z")
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. ---
**Author:** ![Florentine\_Pogen\_1](https://avatars.discourse-cdn.com/v4/letter/f/9e8a1a/32.png) [@Florentine\_Pogen\_1](https://boards.straightdope.com/u/Florentine_Pogen_1)\ **Post date:** [March 11, 2003, 10:20pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/11 "2003-03-11T22:20:18Z")
I say “four speed”. Maybe I’m the only one. ---
**Author:** ![Lagged2Death](https://avatars.discourse-cdn.com/v4/letter/l/ac8455/32.png) [@Lagged2Death](https://boards.straightdope.com/u/Lagged2Death)\ **Post date:** [March 12, 2003, 8:07pm UTC](https://boards.straightdope.com/t/what-does-the-x-stand-for-in-cd-players/160412/12 "2003-03-12T20:07:21Z")
> [@](#): > > \*Originally posted by r\_k \* > \*\*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. \*\* 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.