I’ve been looking at SD cards to use in a surveillance camera. I’ve come across several high endurance models supposedly designed for the constant use with a dash-cam or surveillance camera, like SanDisk’s High/Max Endurance, WD Purple microSD or Samsungs Pro Endurance. But the only distinct feature of those cards seem to be that the warranty period for the lower capacity and/or cheaper models are significantly shorter, usually 2 or 3 years compared to the 10 to life for the standard cards. Obviously in place to avoid the more frequent RMA claims through extensive use they claimed to be designed for. Only the most expensive models like SanDisk’s Max Endurance 128/256GB have comparable warranty periods at about double the cost.
Also what measures, other than extensive over-provisioning, could be taken to “harden” the cards ? MLC memory chips seems to be exclusive to small capacity industrial cards.
I would really prefer a long lasting card, not for the cost of replacing it, but rather to avoid getting out on the 15 foot ladder every 6 month. But if it’s all the same after all…
It depends on the model/brand. It can be anywhere from no different compared to regular consumer models, all the way up to actually pretty impressive endurance rating. If you dig into the whitepapers for specific models, they usually have some really ass-backwards rating like
X hours of FHD Video*
*FHD video is h264 1920x1080 20Mbit/s
or something like that. Combine that with the warranty term to get a rough idea of how many TBW you can expect in a best-case write-through like you do in a surveillance system.
It’s afaik just higher quality nand flash. stuff like 96l tlc vs 2d tlc or 64l qlc. MicroSD cards don’t really have space for complicated controllers, and there’s no wear leveling, so there’s no real overprovisioning afaik.
IIRC, SanDisk Max Endurance and similar very expensive Samsung lines are the only significantly more endurant ones.
This thread is where I collected most of this understanding from.
Also worth noting that, because of the write-through nature of the work, the TBW ratings here are probably closer to DWPD->TBW enterprise ratings, which often far exceed consumer TBW ratings due to different expected use cases.
For your use case, though, you should, in theory, if the specs aren’t a lie, get approximately the rated TBW of the product.
I’d take the level of “endurance” advertised with several grains of salt unless TBW figures are being quoted.
That being said, some microSD cards do actually use MLC (or at least pMLC) instead of TLC and objectively will last longer at a given capacity than the commodity TLC cards.
If I remember right, the sandisk max endurance cards are pMLC while the sandik high endurance cards are just TLC. I just bought a Sandisk “Industrial” which is actual MLC, but it’s capacities are small.
This is only WD’s portfolio, but it does give TBW figures and it shows if the MicroSD card’s controller has advanced features like a health status register or auto/manual read refresh:
I’ve been running some stuff on microsd, that shouldn’t have really been run on microsd (sqlite, workload a couple of gigs read/write per hour, fairly warm, 24/7), and I can say that Sandisk ultra last about a month, and Samsung endurance pro last about a year.
I didn’t bother claiming warranty for a microsd card… in the end I ended up using an old 2.5" sata ssd and a usb-sata adapter instead.