This came up on facebook the other day, how long do SD cards last?
First of all – I have found SD cards to be pretty reliable overall. Not as reliable as SxS cards or XQD cards, but pretty good generally. The physical construction of SD cards has let me down a few times, the little plastic fins between the contacts breaking off. I’ve had a couple of cards that have just died, but I didn’t loose any content as the camera wouldn’t let me record to them. Plus I have also had SD cards that have given me a lot of trouble getting content and files off them. But compared to tape, I’ve had far fewer problems with solid state media.
But something that I don’t think most people realise is that a lot of solid state media ages the more you use it. In effect it wears out.
There are a couple of different types of memory cell that can be used in solid state media. High end professional media will often use single level memory cells that are either on or off. These cells can only store a single value, but they tend to be fast and extremely reliable due to their simplicity. But you need a lot of them in a big memory card. The other type of cell found in most lower cost media is a multi-level cell. Each multi-level cell stores a voltage and the level of the voltage in that cell represents many different values. As a result each cell can store more than one single value. The memory cells are insulated to prevent the voltage charge leaking away. However each time you write to the cell the insulation can be eroded. Over time this can result in the cell becoming leaky and this allows the voltage in the cell to change slightly resulting in a change to the data that it holds. This can lead to data corruption.
So multi level cards that get used a lot, may develop leaky cells. But if the card is read reasonably soon after it was written to (days, weeks, a month perhaps) then it is unlikely that the user will experience any problems. The cards include circuitry designed to detect problem cells and then avoid them. But over time the card can reach a point where it no longer has enough memory to keep mapping out damaged cells, or the cells loose there charge quickly and as a result the data becomes corrupt.
Raspberry Pi computers that use SD cards as memory can kill SD cards in a matter of days because of the extremely high number of times that the card may be written to.
With a video camera it will depend on how often you use the cards. If you only have one or 2 cards and you shoot a lot I would recommend replacing the cards yearly. If you have lots of cards either use one or two and replace them regularly or try to cycle through all the cards you have to extend their life and avoid any one card from excessive use which might make it less reliable than the rest.
One thing regular SD cards are not good for is long term storage (more than a year and never more than 5 years) as the charge in the cells will leak away over time. There are special write once SD cards designed for archival purposes where each cell is permanently fused to either On or Off. Most standard SD cards, no matter how many times they have been used won’t hold data reliably beyond 5 years.
If you use Sony’s SXS cards or USB Hard Drives, Sony have a utility that allows you to check the status of your media and correctly format the media. This is particularly useful for reading the number of cycles your SXS card has reached.
The utility can also copy SXS cards to multiple destinations for simultaneous backups of your content. You can download the utility for free via the link below.
UPDATE – IT IS NOW CONFIRMED THAT THE NEW 440MB/s CARDS WILL NOT WORK UNDER V7 OR EARLIER FIRMWARE. A FIX WILL BE INCLUDED IN VERSION 8.
There have been some comments on an older thread about problems with the very latest slightly faster Sony G series 128GB XQD cards with Sony’s F5 and F55 cameras (thanks Justin and Richard).
Many people, including myself use XQD cards with the Sony QDA-EX1 adapter in the PMW-F5 and PMW-F55 as well as other SxS cameras. Up to now I’ve never heard of any real problems, basically they work pretty much the same as SxS cards.
Very recently Sony released a new very slightly faster XQD cards. The old cards have a maximum write speed of 350MB/s while the new cards have a max write speed of 440MB/s. You can see in the image above of one of the new cards that both the read and write speeds are shown on the front of the card. The old (good) cards only show a single speed (400MB/s).
From what I have been able to gather so far the old 128GB G series cards work just fine, but a few people are reporting that the new faster 128GB ones do not. Problems include being unable to format the cards in the camera or unable to write anything to the cards.
If you have any experience of this issue, good or bad, with the new 64GB or 128GB 440MB/s cards please let me know by adding a comment.
I recently reviewed the rather excellent Sonnet QIO I/O device that allows you to very quickly ingest material from SxS cards, P2 cards as well as SD cards to your computer. Along with the QIO I was sent a Sonnet SDHC to SxS card adapter to take a look at. Now I’m going to lay my cards on the table here and say that I strongly believe that if your going to shoot with an XDCAM EX camera you should be using SxS cards in order to get the best possible reliability. However as we all know SxS cards are expensive, although a lot cheaper now than they used to be, I remember paying £600 for an 8Gb card only 4 years ago!
So ever since the launch of the XDCAM EX cameras, users including me have been trying to find alternative recording solutions. I found that it was possible to use an off-the-shelf SD card to express card adapter (the original Kensington Adapter) to record standard frame rates on class 6 SD cards in the EX cameras. However the SDHC cards stick out of the end of the generic adapters so you can’t close the doors that cover the card slots in the cameras. Following that initial discovery various companies have brought out flush fitting adapters that allow the use of SDHC cards. Then about two years ago Sony openly admitted it was possible to use an adapter in the cameras and released their own adapters (MEAD-SD01 and MEAD-MS01) as well as making some firmware changes that made using adapters more reliable. The key point to consider when using an SxS adapter and SD cards is that the media, the SD cards, are consumer media. They are produced in vast quantities and the quality can be quite variable. They are not made to the same standards as SxS cards. So I choose to shoot on SxS whenever possible and I’ve never had a single failure or unexplained footage loss. BUT I do carry a couple of adapters and some SD cards in my camera kit for emergencies. You never know when you might run out of media or find yourself in a situation where you have to hand over you media to a third party at the end of a shoot. SDHC cards are cheap and readily available. You can buy an SDHC card just about anywhere. I’d rather switch to SDHC cards than try to do a panic off-load to a backup device mid-shoot, that’s a recipe for disaster!
Anyway… on to the Sonnet SDHC to SxS adapter. It feels as well built as any other adapter on the market. It is mostly metal with plastic end pieces that are made from a nice high quality plastic. I have other adapters that use a very brittle plastic and these can break quite easily, but this one appears to be well made. The SDHC card slots into a sprung loaded slot in the end of the adapter making a reassuringly positive sounding click when it’s latched in place. Once inserted the SDHC card is slightly recessed into the adapter. This is good as it helps prevent the SDHC card from being released from the adapter as you put the adapter into the camera. It means that as you push the adapter into the camera you are pushing on the end of the adapter and not on the SDHC card like some other adapters I have used. To remove the SDHC card you simply push it quite firmly, further into the adapter until you hear another click and it then pops out far enough to be pulled out. This is certainly one of the better made adapters that I have come across.
To test the adapter I used some Transcend class 6 SDHC cards as well as some Integral Ultima Pro class 10 SDHC cards. I used the adapter in my PMW-F3 with firmware version 1.10 as some user have reported problems with other adapters and this firmware revision. I was able to completely fill the cards shooting using S&Q motion at 50fps or 60fps using long and short clips with lots of motion. This is I believe the toughest test for these adapters as the recording bit rate is close to 70Mb/s. I had no issues at all with either type of SDHC card and there was very little delay between finishing a recording and being able to start the next, a good indicator of the cards high performance. I also tested recording very long clips to ensure that there would be no issues when the camera breaks the recording into 4Gb chunks. Again, no problem.
So if you are going to use SDHC cards and an SxS adapter I would suggest you consider the Sonnet SxS adapter. It’s certainly cheaper than the Sony adapter. Sonnet are a large business with a wide range of products and a global distributor and dealer network, so you should have no problem finding a local supplier.
I had heard about the QIO some time ago, so I approached Sonnet to see if I could borrow a unit to review. I was given the loan of a Sonnet QIO at NAB. I have been playing with it since then and you know what, it’s a great device. So what exactly is it? Well it is an extension box that allows you to connect a range of peripherals and flash memory cards to your computer via the PCI bus. The reason I wanted to borrow one was because the QIO is one of the few devices (the only device?) that allows you to connect SxS, Compact Flash and P2 cards to a computer using the high speed PCI bus with hot-swappable functionality. Hot Swap means you can eject and remove cards without having to re-boot the computer or do anything else, something that some of the other adapters on the market force you to do.
Installation was very straight forward. On my Mac Pro workstation I had to plug in a small PCI-X card into one of the vacant slots inside the rear of the machine. This is easy to do and should not put anyone off buying the device, it took me all of 5 minutes to plug the card in and install the drivers. Then a short cable runs from the back of the Mac Pro to the QIO and a separate power supply is plugged into the QIO for power.
On my Mac Book Pro I simply slotted the Sonnet express card PCI bus expansion adapter into the express card slot and then connected this to the main QIO unit via the extension cable and installed the drivers, again a 5 minute job, very simple.
If you do want to use it with a Mac Book Pro, you will need a model that has the express card slot. At the time of writing the device only works with Mac’s, but Windows support should be coming very soon. When buying a QIO there are two versions. The desktop version supplied with the desktop adapter or the laptop version with the express card slot adapter. The functionality is the same for both, it’s just a case of which adapter you need. You can buy the alternate adapter should you want both as an accessory.
So, I have it installed, how is it to use?
It’s really extremely straight forward. You simply pop your media into the slot and away you go. When your done with that card you eject it as you would with any other removable media and stick in the next card. On the workstation this was so much better than plugging in my XDCAM camcorder via USB.
Of course convenience is one thing, but how about performance? The QIO is fast, very fast. I was able to offload a full 16Gb SxS card in about 150 seconds, less than 3 minutes to the internal drive on the Mac Pro. That equates to an hours worth of XDCAM EX material in around 3 minutes or 20x real time. The performance for compact flash cards doesn’t disappoint either at around 15 seconds per Gb so clearly the transfer speed is limited by the speed of the CF card and not the connection as would be the case with USB or firewire. If you want to use the QIO for SD cards then you can use the supplied adapter. Again the performance is very good, but not as good as SxS and CF due mainly to the lower speeds of the SD cards.
Laptop Performance and Expansion.
One of the issues with Laptops is how do you expand them? It’s all very well being able to put an SxS card into the express card slot for fast off load, but where do you then put the material? On a Mac Book Pro you do have firewire 800 but this is still nowhere near as fast as the SxS card. As the SxS card is in the express card slot you can’t use it to add an eSATA drive, so your a little stuck. But not with the QIO. You see the QIO has a built in eSATA controller and 4 eSATA connectors on it’s rear. This means that you can plug in one or more eSATA drives to the QIO and transfer directly from the SxS card to an eSATA drive or drives. So now even on my Mac Book I can make multiple eSATA copies of my media at speeds of up to 200MB/s (total). So once again the speed is usually limited by the card and not the interface.
For a real torture test I put two full 16Gb SxS cards into the QIO and offloaded both cards at the same time to the Mac Pro’s raid drive. Where one card had taken a little under 3 minutes, two cards took abut 190 seconds, just a little over 3 minutes. Transferred this way, two cards at a time you could offload 2 hours of XDCAM EX material in around 4 mins, that’s an incredible 30x real time. I tried the same test with CF cards and again there was little difference in transfer speed between one card and two cards.
This is one fast device. If you have lots of media to off-load and backup it’s going to save you a lot of time. If you are a production company that works with large volumes of solid state media it will pay for itself very quickly in saved man-hours. If your working in the field with a Mac Book Pro the ability to connect both the media and eSATA devices at the same time makes the QIO a very interesting proposition. It is well constructed, simple to install and use, what more could you ask for.
Value for money?
That’s a little harder to answer. It depends on how much material you work with. It’s a fairly pricey device at around $800US or £700GBP for a card reader, but the time savings are substantial, especially if you are asking people to back up material at the end of a days shoot. The faster it can be done, the more likely it is that it will be done straight away, rather than put off until later. It’s also a lot more than just a card reader, the eSATA ports make it so much more useful for connecting drives or even a raid array to a laptop. Overall I think it is actually well worth the investment for the time savings alone. 8/10 (it would have been 9/10 if it didn’t require the power adapter). Great product.
I approached Sonnet and requested a loan QIO for this review, which Sonnet provided. I was not paid to write this and the views expressed are entirely my own. Speed tests were conducted using my own SxS (blue) cards with the QIO attached to a 1.1 first generation Mac Pro with an internal 4 drive raid array, or with a 15″ Mac Book Pro.