SD CARDS - Page 1
Forum section: electronics / general

author: grifftech
author_rank: Frequent Contributor
timestamp: October 11, 2015, 02:49:18 am
content: Is it bad to store an SD card in a computer. The card is quite warm after the computer is on for a while.

author: kj6gss
author_rank: Newbie
timestamp: October 11, 2015, 03:00:51 am
content: It really depends on the temperature. The SD slot probably won't be optimized for thermal flow like the HDD or RAM but an SD card can have a wide range of operating temps.https://www.sandisk.com/about/proofQuoteHow hot is your card getting and what is the operating temp?

author: matseng
author_rank: Frequent Contributor
timestamp: October 11, 2015, 04:31:45 am
content: Yesterday I put a micro-sd into a sd adapter and plugged into my laptop. When I removed it a few hours later is was so hot that the plastic in the adapter had deformed. Not sure if this is good or not :-) But it was a cheap Chinese card, so go figure. A real Sandisk Ultra 64GB barely gets lukewarm.

author: kj6gss
author_rank: Newbie
timestamp: October 11, 2015, 05:04:20 am
content: Quote from: blueskull on October 11, 2015, 04:20:47 amCertainly hard to say with so many variables. The technical specifications for that SD card are pretty similar to above.But realistically it's best to not be at the limit of those specifications. The problem with heat though is what "feels hot" can be a wide range in temperature and doesn't necessarily indicate a problem. Of course it shouldn't be ignored either.I wholeheartedly agree with you on using the cards for storage. There are too many ways to kill one, lose one or otherwise abuse it. I always clear my SD cards the first chance I get. The cards I use in my raspberry pi's are only for OS and have the config and image files backed up.I don't think that leaving an SD card in a laptop or desktop is going to outright damage it with heat. If your computer is getting too hot that it damages the card I imagine there are other things that will break first. But it's not the best place for other reasons. My laptop doesn't fit a standard SD card all the way in and I've broken an adapter before.Toshiba Exceria specs:Quote

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 11, 2015, 06:24:44 am
content: I've used a 16GB Sandisk Ultra SD Card for my Chromebook (with hardly any internal space) since the start of the year for all my schoolwork. It heats up to mildly warm (about 35oC) as I leave it plugged in permanently, but its performance is still fine and I haven't seen any problems with it yet.Cheaper brands could be much different though.

author: hamster_nz
author_rank: Super Contributor
timestamp: October 11, 2015, 06:42:34 am
content: I have never found price to be a great indicator of reliability once to are outside of the insanely cheap.I thought it was pretty common knowledge that most cards in the same model (but with different capacities) all have the same silicon, just that the lower capacitiy ones were the ones with high numbers of unusable blocks on them from the factory.....Some people will say that makes high capacity cards more reliable than one of it's low capacity brothers....However every card I have had which has died it has been the controller that has gone south, leaving the data locked away in the now inaccessible Flash.So I now only have two sorts of SD cards... Those that are broken and those that are about to break

author: targ2002
author_rank: Contributor
timestamp: October 11, 2015, 05:05:40 pm
content: I have not seen much of a problem relating to temperature and lifetime of SD card.Different manufacturers have different wear levelling algorithms. This is an important factor.The biggest factor is which type of flash is in the device. Tlc flash doesn't last long. 1k writes. Mlc flash around 10k writes. And SLC 100k writes. There is a big cost difference between each type of flash. The bigger brands of SD card don't tell you want type of flash they use so they can update the device without informing you.Sent from my Nexus 6 using Tapatalk

author: targ2002
author_rank: Contributor
timestamp: October 11, 2015, 05:29:19 pm
content: I agree the SLC flash is very much more expensive. We use them at work. Not all manufacturers tell you what type of flash is used in the industrial grade cards. We had a serious problem where I worked where the manufacturer changed from SLC to mlc and then a couple of years later to TLC. It caused us huge issues and many in field failures.Sent from my Nexus 6 using Tapatalk

author: amyk
author_rank: Super Contributor
timestamp: October 12, 2015, 03:15:13 pm
content: The smaller companies tend to give more details on the type of flash, even the manufacturer and controller in some cases (e.g.http://www.wintecind.com/oem/flash/sd/h6.html). The big ones like Kingston, Sandisk, etc. seem to not want to disclose those details.I agree the price of SLC is ridiculous (2 or 3 times more capacity for the same die area, but costs 10x more?) but IMHO it's worth it for the 10-100x endurance alone.There's an interesting table of flash memory characteristics here:https://wiki.linaro.org/WorkingGroups/KernelArchived/Projects/FlashCardSurvey

author: grifftech
author_rank: Frequent Contributor
timestamp: October 14, 2015, 03:28:08 am
content: The card is getting to about 105° F sorry about the lack of a Celsius reading

author: hamster_nz
author_rank: Super Contributor
timestamp: October 14, 2015, 03:49:18 am
content: 40.5 C

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 14, 2015, 03:53:00 am
content: Quote from: grifftech on October 14, 2015, 03:28:08 amWow, scrolling text!Anyway, 105° F = 40° C, which is a bit hot, but it's still well within most operating temp specs for SD cards.

author: grifftech
author_rank: Frequent Contributor
timestamp: October 21, 2015, 03:12:13 am
content: Thank you for the help

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 21, 2015, 04:22:59 am
content: Heat is NOT conducive to optimizing the life-expectancy of ANY semiconductor. Especially one which is expected to be storing valuable data using such a "soft" scheme as microscopic charges on floating gate structures. IMHO, it is categorically undesirable to subject memory products to unnecessary heat.