Subscriber Discussion

Flash Devices For In-Camera Recording

Cameras that record internally to flash devices have been around for a while. The process of writing and then overwriting continuously is fairly stressful on devices that do generally have a stated limited life.

Does anyone have experience with in-camera recording to flash and any recommendations at to which devices work well in this service?

Paul, you are referring to edge recording / using SD cards, yes? And are you asking about which cameras work the best or which flash / SD cards are the best?

Sounds to me like he's asking for experiences with reliability of various SD cards...

Matt Ion is correct. I am curious as to experience with various types of SD cards in edge recording (or actually any recording) application. I have an associate who is sugggesting to use of very high end, long life devices, which are both small (4GB) and expensive. I'd much prefer something less esoteric.

Paul, can you mention the name of the device you have under consideration?

From our experiences, low end SD cards, like the ones you get at a trade show or at corner store, have real problems with IP cameras. Cards from San Disk or other brand name vendors do not.

That said, I do not know anyone has a multi-year, long term, study of SD cards with IP cameras but certainly at least a handful of such deployments exist.

There are basically two types of flash memory (although it is more complicated than this in reality) : Single-Level Cell (SLC) and Multi-Level Cell (MLC) devices. MLC devices can store more bits per cell and so are cheaper to manufacture for a specific memory capacity. They are less robust than SLC devices and have a much smaller number of write cycles before they start to fail. SLC cards have a much higher number of write cycles and are often advertised as "industrial-level" cards. But beware - some MLC cards are also advertised as industrial level, simply having a wider operating temperature range and other characteristics that involve more technical detail than I care to go into here. (Which is another way of saying "beyond my level of competence" !)

It's funny you mention SanDisk... I put a SanDisk 32GB UHS-1 microSDHC card in my phone and partitioned it so the phone could use part of it as system storage (a function built into the phone kernel). Before long I started having issues, with the phone randomly reporting "SD card removed" when it went to sleep. Exercising my Google-fu, I discovered a litany of complaints from other SanDisk microSD users, particularly to do with Class 10 cards, having data loss issues in their phones. To SanDisk's credit, pretty much everyone reported that the faulty cards were replaced under warranty, but by then many had moved on to other brands.

I have used SD cards in some low end domestic camera's/VMS's and have found that some will only recognise SanDisk cards or thumb drives (on the VMS) :-(

Discovered that recordign in Continuous mode is recomended, becauuse motion detection causes tte camera to create a file every time a MD video clip is generated, thus filling the SD cards in few hours.

Some brands (like Flir's Digimerge) offers 2 Format modes: SD Video and EXT3. In small capacity SD cards (2 GB) both can be used but in a 64GB SD card I could only format in SD Video format, causing that a D1@5 fps videoclip using more than 700 MB/hour.

Still testing, but be careful when proposing long storage (days) on SD cards!