EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Halcyon on November 21, 2016, 10:43:43 pm
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I need a replacement microSD card for my car dash cam. The one that came with it is beginning to fail, it's just some cheapo no-name Chinese thing (although it has lasted quite a number of years).
I was looking at the "industrial" cards by Kingston and Sandisk but noticed that both their industrial/high endurance cards and their "standard" cards claim operating temperatures up to 85°C. As far as I know, both types also use MLC flash. So what's the difference (apart from a lower limit operating temperature)?
Since it's going to be sitting in a hot car especially during summer (today is going to reach up to 37°C outside), I want something that will last but I'm not going to waste my money on something that isn't needed.
Interestingly the "industrial" card from Kingston has a 5 year warranty, while the standard one has a limited lifetime warranty.
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I have a feeling the 'consumer' ones use TLC. The speeds are lower and the capacities are much higher. The endurance should be better with the MLC, but it is interesting they are willing to do a lifetime warranty on the consumer level one but only 5 years for the supposedly more durable industrial one. Probably due to physical damage though - in a true industrial environment there's a much greater chance of physical damage to the card.
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At my place of employment, we had a device that required the use of Wintec Industrial Grade SD cards. The reason given by the vendor was that the Industrial Grade cards had built-in wear leveling, while the consumer grade cards did not. I don't know if it was true, but I know that they cost a LOT more. Thankfully, we no longer have that device.
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At my place of employment, we had a device that required the use of Wintec Industrial Grade SD cards. The reason given by the vendor was that the Industrial Grade cards had built-in wear leveling, while the consumer grade cards did not. I don't know if it was true, but I know that they cost a LOT more. Thankfully, we no longer have that device.
Some cards do some internal wear leveling which is transparent to the operating system but it's not part of the SD standard at all, it's basically down to whether the card manufacturer wants to include it or not. I think even the consumer TLC type cards do wear leveling to counteract the less durable TLC technology.
Anyway thanks for your advice guys. I might just stick with a standard Sandisk card. If it means I have to replace it every 5 years instead of every 8, it'll still save me stacks of money.
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With consumer grade cards you shouldn't store any remotely important information for prolonged times. They may corrupt your data as soon as just one year sitting in storage.
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AFAIK, there is no card on the market that doesn't have wear leveling.
NAND Flash is so shitty (mere thousands of write cycles), the only reason it exists as a viable product, at such a low price point, is entirely because of wear leveling (and error detection and correction, which have been a vital part of mass storage for decades).
Curious about that warranty business. It could be that the products are physically identical, but the industrial one carries a stronger warranty (in terms of products/costs/liabilities they will cover) than the other. When you're paying for the fine print... I suggest reading it, in great detail! Then you will perhaps discover what you're paying for (or not!).
Tim
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I think its more about continuous writes than temperature issues. There are a few cards that are commonly recommended, Lexar 633x and transcend/sandisk high endurance.
Transcend/sandisk is only 2 year and lexar is lifetime warranty. It could be because they specifically say it can be used with security cameras that they limit the warranty (lexar doesn't).
You can see below with standard cards warranty is voided:
https://www.carcamcentral.com/guide/recommended-sd-cards-avoid-sandisk-ultra-cards (https://www.carcamcentral.com/guide/recommended-sd-cards-avoid-sandisk-ultra-cards)
Manufactured using top-tier MLC NAND flash chips, the high endurance microSDXC/SDHC card is capable of standing up to 12,000 hours of Full HD video recording
If you drive 3hr per day thats 10 years of recording.
For a security camera, its probably similar if you are using motion detection (assuming a write buffer). If no write buffer or motion detection its only 1.4 years.
https://static.bhphotovideo.com/lit_files/112966.pdf (https://static.bhphotovideo.com/lit_files/112966.pdf)
https://static.bhphotovideo.com/lit_files/113223.pdf (https://static.bhphotovideo.com/lit_files/113223.pdf)
https://www.transcend-info.com/Products/No-727 (https://www.transcend-info.com/Products/No-727)
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Ended up ordering the Transcend 32GB High Endurance cards. For $35 each (including delivery) it's not much more than the cheapest 32GB card that Officeworks has at $20 each and it's still cheaper than the Sandisk Extreme 32GB.
If anyone is interested, Kogan (https://www.kogan.com/au/buy/transcend-32gb-high-endurance-microsdxcsdhc-ts32gusdhc10v-transcend/) is listed as an authorised reseller according to Transcend's website.
EDIT: Do not give Kogan an e-mail address you care about! They will send you numerous spam e-mails daily and their unsubscribe function does nothing. Read more about it at this thread (https://www.eevblog.com/forum/chat/kogan-sending-out-spam/) .
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I believe the main difference between an 'industrial' card and an off-the-shelf consumer card is availability.
If you buy an industrial card, and then buy another one a month later, they should be the same. Really, identically, the same.
If you buy consumer cards, then on each occasion you'll get whatever die the manufacturer chose to use for that batch. They might be the same, or one might be a die shrunk version, or have a controller from a different supplier. You just don't know, and while both might work perfectly well in your PC or camera, if you have a product which hasn't been designed for the widest possible compatibility, it might have issues.
Testing and certifying individual memory cards for use in an industrial application is a colossal time sink... trust me on this!
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I find the consumer type cards last around 18 months before they get worn out, as the most common camera types write the data to the card and only update the FAT at power off or when they reach the recording limit. That reduces the wear on the FAT sectors a lot, as you do not have a FAT write with each block write like the FAT standard calls for.
Of course that means that in an accident if the camera is damaged and does not finish the write and update you will need data recovery software to find the last file and read it out.
I just buy around 5 cards at a time, and rotate them whenever I pull the card to get worthwhile footage off it.
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i can recommend transcent card (or how the get spelled). :-+
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Being an old codger, I treat the SD card in my camers like film. It gets used once, then when it fills up I buy another. For the amount of pictures I take, its cheap enough.
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Being an old codger, I treat the SD card in my camers like film. It gets used once, then when it fills up I buy another. For the amount of pictures I take, its cheap enough.
I once met someone who had a similar theory...but with vacuum cleaners. :-DD
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Being an old codger, I treat the SD card in my camers like film. It gets used once, then when it fills up I buy another. For the amount of pictures I take, its cheap enough.
Stop being cool with your fancy fancy SD card. If you really want to be crazy, burn it straight onto PROMs (No Es here).