SD Card's Future for Video Surveillance Storage

•Published Aug 18, 2009 00:00 AM

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SD cards are gaining attention as their use in the consumer world for digital cameras, smartphones and laptops increases significantly. In the video surveillance market, it is becoming increasingly common for IP cameras to support SD cards and, with that, interest in storing video inside the camera itself.

Are we quickly moving to a world where centralized storage dies and storage moves to the camera?

In this report, we examine what the video surveillance market will look like in 2014 - 5 years from now - analyzing the barriers that need to be resolved, projecting advances in features and pricing and analyzing the competitive position of SD cards versus other forms of video surveillance storage.

Today, in 2009, SD cards storage for IP cameras almost certainly represents less than 1/10 of 1% (.1%) of new deployments. By 2014, we project that SD cards in IP cameras will replace traditional centralized storage in a few niches, remaining a distinct minority. However, by that time, SSDs will start to be seriously considered as a replacement for hard drives in video surveillance.

We estimate that currently, the average video surveillance system uses 60 GB to 240 GB per camera, with megapixel cameras routinely requiring 600 GB or greater storage [For details, review our report on how much storage is needed for video surveillance cameras.]

Let's compare that to storage capacity available today. Our focus will be on hard drives and SD cards. While SSD is an alternative form factor gaining popularity for laptops, the size of these units (comparable to hard drives) makes SSDs unlikely to ever be widely used inside of cameras. Indeed, an argument may be made that SD cards are still too large and that mini SD cards will be the most likely used for IP cameras. Nonetheless, since most IP camera manufacturers are currently electing to use SD cards, we shall focus on SD in this analysis.

In August 2009, the end user price for SD cards (according to Amazon) are:

4 GB: $5 - $13 USD
8 GB: $12 - $24 USD
16 GB: $30-$40 USD
32 GB: $80 - $100 USD

In August 2009, the end user price for Hard drives (according to Amazon) are:

500 GB: $60 - $100 USD
1 TB: $80 - $130 USD
1.5 TB: $130 - $200 USD
2 TB: $230 - 260 USD

Currently, the most cost effective options for SD cards is the 8 GB unit and, for hard drives is the 1 TB unit. On a per GB basis, the SD card is 21x more expensive than the hard drive [note: this is only one metric in the comparison].

For production use today, while hard drives are used everywhere in video surveillance, SD cards are rarely used or supported. Hard drives are used in DVRs, NVRs, servers running IP video software, NAS and SANs connected to video surveillance systems, etc. Only a few VMS systems currently support SD card storage and no VMS system today supports SD storage from 3rd party cameras (i.e., Mobotix's Control Center VMS supports Mobotix cameras with SD cards but Milestone, Genetec and OnSSI support no camera manufacturer's SD cards storage). With support so limited, today's users of SD cards often need to use the IP camera's web interfaces or physically pull the SD card from the camera when conducting an investigation.

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In 2009, hard drives have significant advantages against SD. Storage capacity of SD cards are insufficient for all but the lowest demanding use cases. The cost per GB is dramatically more for SD than hard drives. Finally, VMS support for SD cards is extremely limited.

Projecting the Market in 2014

Clearly, SD cards need to close a significant gap to catch hard drives and become broadly used in the video surveillance market. The key question becomes, "How much of this gap will SD cards close by 2014?"

Let's make some projections of where various components will be by 2014:

Hard drives: 4 TB hard drives at $100 USD seems reasonsable, if not a conservative estimate (given the current availability of 2 TB drives and historic patterns).
SD cards: A number of IT analysts project that capacity/price performance will increase by up to 50% per year. Over a 5 year period, that would result in an 800% increase in capacity at today's prices (double what we estimate for hard drives). This would imply a 128 GB SD card for $30 - 40 USD.
Megapixel cameras: By 2014, HD 1080p cameras should be fairly commonplace. The cameras will certainly be less expensive, have better low light capability, more efficient streaming and use of H.264, etc.

With cheaper hard drives and better/cheaper megapixel cameras, storage consumption will increase. While today's per camera storage consumption is in the 60 GB to 240 GB range, this should easily increase by a factor of 4 to 600 GB or more per camera.

Note: By 2014, the consumer market may widely adopt SSD as a replacement for storage in laptops. However, this trend is unlikely to carry over to video surveillance. First, SSD will offer 2-4 times the storage as SD cards for the same price, making SSD laptop storage cheaper than IP camera storage. Secondly, for many (most?) laptops (and netbooks), 256 GB will be way more than sufficient. However, this will not be the case with IP cameras.

Constraints of SD Cards

Even in 2014, a number of specific constraints will still limit the use of SD cards.

Higher Priced Storage

While the gap between SD card and hard drive storage is likely to decrease significantly, it will not be eliminated. For cameras were lower storage is acceptable (say 60 GB to 120 GB), the price increase for storing in SD cards may be as low as $30 USD per camera.

Higher Priced Cameras

Cameras that support SD cards will likely remain more expensive than cameras that do not. However, the price differential could become fairly minor - end user price of no more than $20 or $30 USD. This increase would be in addition to the storage cost.

Inefficiency in Using Storage

The increase in cost would likely be higher than the estimates above if users over-provision storage in cameras. Over-provisioning storage may be necessary to ensure that all cameras meet quality and duration requirements.

This problem arises when storage 'pooling' common to DVRs and NVRs is replaced by storage on-board cameras. Even with the same camera settings, some cameras will always consume more storage than others. If the average storage consumed is 60 GB per camera, some will consume 40 GB but a few will consume up to 120 GB. This is unpredictable and happens because of changes in activity, lighting, noise that occurs at some cameras rather than others. With centralized storage, this is less of an issue because the storage is pooled. However, with storage on-board cameras, cameras demanding more storage to hit the resolution/duration requirements will have to sacrifice one of those two requirements or purchase a potentially much more expensive SD card.

Restrictions on Video Recording Quality/Duration

It's unlikely that 5 years from now, SD cards will cost-effectively provide more than 256 GB of storage. This becomes a significant problem for anyone using megapixel cameras. At 128 GB of storage, this provides 1 week of H.264 storage (even assuming more efficient CODECs and future improvements at handling low light and high motion scenes).

By 2014 deployments will use megapixel cameras for at least a percentage of cameras (and this could be a significant percentage - 25% or more). For these deployments, SD cards will likely remain unsatisfactory while hard drives will easily support these cameras.

Constraints on VMS Systems

As capacity for SD cards increases, motivation for VMS vendors to support SD cards will improve. However, implementation issues will constrain widespread support. Specifically:

No standards for accessing 3rd party storage. In 5 years, this may occur but not only do you need the standard to be developed, it will still take years for it to be widely adopted.
Managing remote storage can be complex, especially given the range of implementations that various vendors use.
Accessing remote storage may result in poorer performance for search/investigations. VMS vendors analyze and mark video they store internally to enable advanced search functions (histograms, thumbnails, etc.). remote storage may not support these functionalities.

While VMS support for SD cards will certainly improve, how much or how little remains a real risk.

2014 Core Applications of SD Cards

The advances in SD card performance should expand their use in a number of sectors where lower storage capacities or larger off-setting problems are key.

Home/SMB

In the home and small business markets, storage requirements tend not to be great but the demand for installation/management simplicity is. Today's video surveillance systems can be complex and expensive to deploy with a DVR or dedicated PC need for a few cameras. On-board storage with 32 GB or 64 GB should be far more than enough for most home and SMB customers. Plus, with storage on-board, the DVR and/or dedicated PC can be eliminated - generating significant up-front cost savings and plug n play deployments.

Wireless/Mobile Deployments

The first adopters of SD cards today are for applications where bandwidth is severely constrained or unreliable. As SD card capacity increases, this will make for an ideal solution for these deployments. Moreover, this should spur on deployment of cameras in areas where poor network connectivity previously made using cameras unfeasible - expanding the market.

Conclusion

By 2014, the gap between SD cards and hard drives should diminish significantly, enabling expansion into a number of important market segments. However, major limitations are likely to remain preventing its widespread use in most mainstream video surveillance applications.