# Do rewriteable CDs "wear out?" **URL:** \ **Category:** Factual Questions\ **Created:** [December 29, 2002, 11:02pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563 "2002-12-29T23:02:22Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![KidCharlemagne](https://avatars.discourse-cdn.com/v4/letter/k/ed8c4c/32.png) [@KidCharlemagne](https://boards.straightdope.com/u/KidCharlemagne)\ **Post date:** [December 29, 2002, 11:02pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/1 "2002-12-29T23:02:22Z")
Can I keep writing/erasing ad infinitum or is there something physical that will wear out from continued rewrites? Thanks. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 29, 2002, 11:20pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/2 "2002-12-29T23:20:20Z")
Yes, although in my experience they are likely to perish from wear to the external surfaces before the recording medium packs up. Essentially the recording medium in a CDR is a material that, when heated and cooled in one way, reflects light more than when heated and cooled another way; repeated cycles of heating and cooling will eventually break down the material chemically or otherwise. ---
**Author:** ![KidCharlemagne](https://avatars.discourse-cdn.com/v4/letter/k/ed8c4c/32.png) [@KidCharlemagne](https://boards.straightdope.com/u/KidCharlemagne)\ **Post date:** [December 29, 2002, 11:23pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/3 "2002-12-29T23:23:12Z")
Are we talking hundreds or thousands of rewrites? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [December 29, 2002, 11:23pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/4 "2002-12-29T23:23:17Z")
There are real limits to the number of times that a CDRW can be re-writen but they are so far beyond the number of R/W/RW cycles any user would typically do during a lifetime of use it’s really sort of a waste of time to worry about hitting this limit for most people. If you had the CDRW disk in a system 24/7 and you are using a utility that makes it mimic a hard disk there might be reason to be concerned. Between 1,000 to 10,000 re-writes are the limits I have typically heard used for CDRWs depending on the media (IIRC some formulations are rated to have more RW cycles than others) ---
**Author:** ![KidCharlemagne](https://avatars.discourse-cdn.com/v4/letter/k/ed8c4c/32.png) [@KidCharlemagne](https://boards.straightdope.com/u/KidCharlemagne)\ **Post date:** [December 29, 2002, 11:25pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/5 "2002-12-29T23:25:10Z")
Great. Thanks all. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 29, 2002, 11:33pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/6 "2002-12-29T23:33:01Z")
If used in packet write mode though, the data is continually erased and overwritten as (in some respects, at least) the disc is used like an ordinary rewritable hard drive; the CDs may wear out quicker that way. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [December 29, 2002, 11:45pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/7 "2002-12-29T23:45:32Z")
I bet the ones made by the real manf like Sony last longer than cheapo ones. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 30, 2002, 10:50pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/8 "2002-12-30T22:50:52Z")
I’m informed that the reason that the coatings on CDR/RWs are all different colours depending on who you buy them from is that each manufacturing company, having devloped a phase-change dye/wax (or whatever it is actually called), patents the formula; another company wanting to make similar media without entering into a licence agreement, must develop their own solution. If this truly is the case, I’d imagine that the performance of certain types is better than others. ---
**Author:** ![World\_Eater](https://avatars.discourse-cdn.com/v4/letter/w/f04885/32.png) [@World\_Eater](https://boards.straightdope.com/u/World_Eater)\ **Post date:** [December 30, 2002, 11:01pm UTC](https://boards.straightdope.com/t/do-rewriteable-cds-wear-out/145563/9 "2002-12-30T23:01:29Z")
My computer always “coasters” TDK CDs for some reason.