Solid State or Flash Memory

For all you file based camera operators out there: have you ever thought much about the solid state memory cards you’re using these days? Me neither. I recently read a white paper that talks about the two different types of flash memory which are:

SLC — single level cell

MLC — multi level cell

You might think that multi level is the more reliable and more expensive memory but that is not the case. It would seem that single level memory is 10 times more reliable than multi level because of the superior ability to keep the voltage charge in that cell from leaking away over time. Carrying that thought over to the binary side of the technology it would also seem that the absence of voltage from a cell is a zero (0) and the presence of voltage is a one (1).

These two types of flash memory are found in

Sony SxS

Panasonic P2

SDHC

CF — compact flash

Did you know that Panasonic’s P2 cards are actually 4 SDHC cards in a case with an integral controller? Me neither. Panasonic makes an economy version of their P2 cards called amazingly enough, the P2e. Sony just brought out their lesser cost SxS cards called SxS-1.

Okay, so.….…

Assuming that the more expensive SxS is single level cell technology and the less expensive one is multi-level cell tech then there are distinct advantages in favour of the higher cost ones:

better endurance
more extreme operating temperature range
lower power consumption
faster write/erase speeds
longer write/erase endurance — 100,000 cycles as opposed to 10,000 for the SxS-1
If the SxS-1 card is operating in higher than recommended temps there is a real risk of losing data. MLC technology is considered consumer grade and SLC is industrial grade. Cool, huh? Everything you never wanted to know about solid state memory but I told you anyway.

Here’s the link to the white paper:

http://www.supertalent.com/datasheets/SLC_vs_MLC%20whitepaper.pdf

Oh yes, and Sony is on the verge of releasing their brand new solid state memory tech called ‘SR’ media for use with their soon to be released SRW-9000PL solid state recorder that will attach to the backs of Sony’s high end digital cinema cameras, including the new XDCAM EX PMW-F3. Sony is calling their SR media groundbreaking and I’m inclined to agree. The cards can be up to one terrabyte in size and can transfer data at an astounding 5.5 gigbits per second. By comparison, SxS Pro memory cards transfer 800 megabits per second. SR memory is also touted as having an extremely high reliability factor.

http://www.macvideo.tv/camera-technology/news/index.cfm?newsId=3249777


Written by:

Don Greening is the owner and both senior editor and videographer for Reeltime Videoworks. His arts background as a classical musician and composer gives him an uncompromising eye and ear for detail that is very important in video production. Don also hones his technical skills by updating them through courses at Emily Carr Institute of Art + Design.

  • I really wish there was one format to rule them all. Of course this won’t ever happen, a diversity of formats is needed, but I’m glad there are people like you out there gathering all the information so I don’t have to!