CD-ROM drives, which today typically means a CD-RW drive that is a combo CD-ROM, CD-R and CD-RW drive, come in a variety of speeds. The original drive (1x) transferred data at 150KB per second. By doubling the spindle speed (RPMs) for 2x drives, the transfer rate increased to 300KB/sec and has been increasing ever since. See CD-ROM and DVD drives.
What Do 40/12/48 or 40x/12x/48x Mean?
CD-RW drives have three speeds that are designated with three numbers or sometimes three "X" numbers; for example, 40/12/48 or 40x/12x/48x." The numbers are write/rewrite/read speeds.
A Lotta X's
This is the label from a Memorex combo CD and DVD drive in 2005. Each "X" number means the speed for that format is X times 150KB for CDs and X times 1.35MB for DVDs.
X Data Transfer
Rating Rate
1x 150 Kilobytes/sec
2x 300 Kilobytes/sec
4x 600 Kilobytes/sec
8x 1.2 Megabytes/sec
10x 1.5 Megabytes/sec
12x 1.8 Megabytes/sec
20x 3.0 Megabytes/sec
36x 5.4 Megabytes/sec
40x 6.0 Megabytes/sec
48x 7.2 Megabytes/sec
50x 7.5 Megabytes/sec
52x 7.8 Megabytes/sec
What Do 40/12/48 or 40x/12x/48x Mean?
CD-RW drives have three speeds that are designated with three numbers or sometimes three "X" numbers; for example, 40/12/48 or 40x/12x/48x." The numbers are write/rewrite/read speeds.
First X / Second X / Third X
CD-R write / CD-RW write / CD-ROM read
A Lotta X's
This is the label from a Memorex combo CD and DVD drive in 2005. Each "X" number means the speed for that format is X times 150KB for CDs and X times 1.35MB for DVDs.
 | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2008 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- IBM claims 'Quicksilver' flash sets data-speed record
- A project under development from IBM is setting new records for data-transfer speeds using solid-state technology with one million input/outputs per second. IBM has said its 'Project Quicksilver' is setting new records for data-transfer speeds on solid-state technology, with its tests showing a disk-storage solution hitting one million input/outputs...
- News items 2008-08-29
- MSD Organizer Freeware (zip)
- MSD Organizer Portable Freeware is a personal and professional information manager to be installed in Pen Drives, with the following modules: Calendar, Contacts, Alarms, Tasks and Cards. It also provides the following tools: backup and restore, word processor, spreadsheet, image viewer, calculator, and financial calculator. The program will allow you...
- Software downloads 2008-08-29
- First images of Google-powered HTC Dream
- It was rumored that the HTC G1 Dream would be the first Google powered phone on the market, and if everything pans out, those rumors will end up being true with a launch date sooner than later. Android Guys have the first mock-up drawings of the Dream, and it's...
- Blog posts 2008-08-28
- Sangeetpedia-Encyclopedia of Indian Music (rar)
- Sangeetpedia features: Fully searchable, easy to use layout. 60+ Ragas & 23 Talas, defined and demonstrated. Install on hard drive or run from DVD-ROM. Packed with 8 gigabytes of video/audio/images. 1,250 fundamental terms of Indian Music. 685 rare and often unseen images. 220 high quality audio files. 425 high resolution...
- Software downloads 2008-08-28
- MP3 Remix for Windows Media Player (exe)
- Enjoy your favorite songs in new and exciting ways by remixing them. Even if you have no musical ability, with MP3 Remix you can easily create and record beautiful and original interpretations of any song in your MP3 or CD music library. MP3 Remix lets you easily add beats, loops,...
- Software downloads 2008-08-28
- Palm Treo Pro (unlocked)
- Photo gallery:Palm Treo ProWhile not the best-kept secret in the technology world, with leaked photos and videos all over the Net, we were still amped over Palm's official unveiling of the Palm Treo Pro. And why wouldn't we be? The smartphone looked pretty sharp, both inside and out. However, now...
- Product reviews 2008-08-27
- Can you trust kids with a Kindle?
- Can you trust kids with a Kindle?Can you trust kids with a Kindle?I agree with you for the most part. An electronic book or ereader would be good for looking up information to reference. The drawback I see is the price tag of the kindle, and if someone...
- Discussion threads 2008-08-27
- Virtualization software revives dumb terminals, cuts IT costs
- Virtualization software revives dumb terminals, cuts IT costsMicrosoft puts out a free tool that does essentially the same thingSteadystate... google it. We currently use it on kiosk computers, but you could use it for what they are pushing it for. You could also deploy group policies that prevent...
- Discussion threads 2008-08-27
- Malware detected at the International Space Station
- Malware is reaching new heights, and going into Space through a removable media carrying the W32.Gammima.AG password stealing malware to the International Space Station. According to SpaceRef.com : "W32.Gammima.AG worm is a level 0 gaming virus intended to gather personal information. Virus was never a threat to any of...
- Blog posts 2008-08-26
- Microsoft to target Windows XP Pro users with Genuine 'nagware' notifications
- Microsoft to target Windows XP Pro users with Genuine 'nagware' notificationsI don't know what difference it will makePeople who love Windows will still love Windows. People who hate Windows will still hate Windows. People who pirate Windows will still pirate Windows.RE: Microsoft to target Windows XP Pro users with Genuine...
- Discussion threads 2008-08-26
- MSD Organizer Portable (zip)
- MSD Organizer Portable is a personal and professional information manager to be installed in pen drives, with the following modules: calendar, contacts, alarms, tasks, cards, diary, property, budget, health and music. It is very easy to use and allows to personalize many features to fit your personal preferences. It allows...
- Software downloads 2008-08-26
- IDF and the new Mac notebooks
- IDF and the new Mac notebooksI hope the optical drive rumor isn't true...I hope the optical drive rumor isn't true, I want mine integrated.RE: IDF and the new Mac notebooksHmm...Virtually every PC maker has a quad core laptop.Virtually every PC maker has ram support of at least 8GB in their...
- Discussion threads 2008-08-25
- IDF and the new Mac notebooks
- The Intel Developer Forum makes it clear what Apple's new notebooks - which I predict will be announced Tuesday, September 16 - will offer. Will it be worth the wait? If longer battery life and higher performance are important to you - yes. And if you weren't...
- Blog posts 2008-08-25
- X-Box (and Cell Phone) Nation: Election Rests In Digital Hands
- The Democratic convention gets started tonight and in the constant quest for the unconventional technological means of getting out the youth vote, the X-Box is today's "in" device. By itself, this may not be a big deal. There are about 12 million X-Box members around...
- Blog posts 2008-08-25
- Vertical line issue also plagues some iMacs
- Vertical line issue also plagues some iMacsWhat part is breaking?The video chip on the mobo or the LCD?Good spooky story timingMy four year old Dell LCD monitor (1704FPTT) began displaying a vertical yellow line, or two, recently. Mine is still sporadic, but I'm sure it will stay or get...
- Discussion threads 2008-08-25
- Google and Sirius XM: Build my "Dream" Handheld
- The current rumor-mongering seems to indicate that HTC's "Dream" will soon be making landfall in the US. Based on the initially leaked specs of this device, it still sounds like it doesn't do what I really would want it to do in order to replace by Blackberry 8820. ...
- Blog posts 2008-08-24
- Maxtor Central Axis NAS server
- The Maxtor Central Axis carries a list price of $320, but can be found for as little as $270--a good deal for a network storage device with 1TB of storage. We liked the Central Axis' compact design, fast performance, and that its over-the-Internet access service was easy to set...
- Product reviews 2008-08-22
- M-Audio Studiophile AV20
- We recently auditioned the M-Audio's Studiophile AV 40 stereo speakers, and found a lot to like. Those big, beefy monitors were great for audio from a PC or any other stereo audio source. However, with 4-inch woofers and speakers weighing 14 pounds each, the AV 40s required a design and...
- Product reviews 2008-08-22
- Belkin GoStudio
- If you're a musician, amateur podcaster, or college student looking for a way to capture CD-quality recordings on your iPod, the Belkin GoStudio is an all-purpose solution with some impressive bells and whistles. The GoStudio is not without its flaws, but at $120 you're likely to take its shortcomings with...
- Product reviews 2008-08-22
- My Awesome IT Job: Vice president of Operations, Limelight
- Hey, we all complain about work from time to time; we've all had lousy jobs. But before you call it a day and head off to the support group that meets at the bar, here are a few words from an IT pro that loves their work. ...
- Blog posts 2008-08-22
Neighboring Terms
Premier Vendor Content Whitepapers, webcasts & resources from our Power Center Sponsors
-
-
Tasty Baking’s new LEED factory
0:57
Tasty Baking CIO: Brendan O’Malley
-
Balancing act: innovation vs. reliability
1:28
Facebook VP of technical operations: Jonathan Heiliger
-
Securing data at E-Loan
1:47
E-Loan CIO: Jay Shah
-
When crops are scarce
1:47
Del Monte Foods CIO: Marc Brown
- View all CIO Vision Series Videos »
