Talk:SD card

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SD card was nominated as a Engineering and technology good article, but it did not meet the good article criteria at the time (March 27, 2015). There are suggestions on the review page for improving the article. If you can improve it, please do; it may then be renominated.

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Text has been copied to or from this article; see the list below. The source pages now serve to provide attribution for the content in the destination pages and must not be deleted as long as the copies exist. For attribution and to access older versions of the copied text, please see the history links below.

Merged MiniSD (history) → SD card
Merged MicroSD (history) → SD card

X Speed Ratings: SLC vs MLC,?

Probably, a thing related to speed ratings of SD cards is the SLC vs MLC issue. Although it is almost never mentioned by SD cards distributors, it seems the critical factor impacting access times, write and read speed, as well as the media durability. I'm absolutely not any kind of expert here, I just wanted to give a hint, hoping it's usefull for soemone more knowledgable. I can't say what is the link between 60, 133, 150x etc. ratings and the SLC/MLC, but there is something on here it seems. Or are the MLC not present on the market anymore?

Searching for "slc mlc sd" gives eg. this document: The Samsung SLC NAND Flash Advantage.

Compatibility section

I think there should be a separate section on compatibility, e.g. between SD and MMC cards, the issue with 128 GB and larger SD cards, etc.

performance-loss with reformating

In SDUC > exFAT filesystem, it is mentioned twice that one can reformat the card. It is however not mentioned that one needs to know the exact specs (like allocation unit size and erase block size) of an SD-Card to do so, or lose up to 50% performance. Said specs are usually not profided by the vendors, even if asked, you have to guess them with flashbench.

Separate CSD Section

Card Specific Data deserves its own section in my opinion. All related matters like declared capacity may reside there. Siavoshkc (talk) 06:28, 10 February 2024 (UTC)[reply]

UHS-I DDR200 Controller

It is said in the article, that

"There is a proprietary UHS-I extension, called DDR200, originally created by SanDisk that increases transfer speed further to 170 MB/s. Unlike UHS-II, it does not use additional pins. It achieves this by using the 208 MHz frequency of the standard SDR104 mode, but using DDR transfers. This extension has since then been used by Lexar for their 1066x series (160 MB/s), Kingston Canvas Go Plus (170 MB/s) and the MyMemory PRO SD card (180 MB/s)."

There are also UHS-I microSD cards from Samsung (EVO Plus, Pro Plus, Pro Ultimate) which achieve speeds above 104 MB/s but are probably not compatible with the DDR200 specification. Such speeds are achievable only on Samsung readers (included with the card), and not on regular DDR200 readers (like Kingston MobileLitePlus). 83.242.66.85 (talk) 11:31, 13 March 2024 (UTC)[reply]

Any body knows any details? — Preceding unsigned comment added by 83.242.66.85 (talk) 22:33, 13 March 2024 (UTC)[reply]

Bad article format

The "History" section of this article is useless garbage, because it persistantly references terms and acronyms which are not defined until much later in the article. The article should be reformatted to move history to the end, so that the reader knows what the different terms mean. — Preceding unsigned comment added by 2601:589:300:C7C0:21A1:13AE:687F:5058 (talk) 20:03, 24 March 2024 (UTC)[reply]

Incomplete, or bad English syntax statement?

The statement "Without they are guaranteed to at least reach A1 speeds", in the 16:11, 25 April 2024‎, version (https://en.wikipedia.org/w/index.php?title=SD_card&oldid=1220735921) of this article, doesn't make sense. The statement is found under the Speed section (section 3), Class subsection (subsection 3.2), "Application Performance Class" sub-subsection. Did the author/editor perhaps mean to write something like "Without host driver support, A2 cards are guaranteed to at least reach A1 speeds"? Mercy11 (talk) 10:05, 26 April 2024 (UTC)[reply]

SD 7.0 does not support UHS-II/IIIcards

SD Express cards cannot support UHS-II interface. SD7. 0 and SD7. 1 define full size SD and microSD form factors using two power supplies, a traditional 3.3 volt and 1.8 volt. 112.104.98.124 (talk) 08:33, 9 October 2024 (UTC)[reply]