UHS II – is it fast enough?

One of the limiting factors when shooting high frame rates is the camera to memory card write speed, this is when your camera starts off fine and then after 10 or so shots it suddenly slows down, or buffers to give it a slightly technical term. When this happens the only thing to do is wait and let the buffer clear, not an ideal solution when you’re missing shots, well UHS II may be that solution but, does it offer all it claims.

UHS Stands for Ultra High Speed and UHS I and II refer to the bus (communication) speed between the card and your device. In practice, this means that a UHS I card can have a read/write speed of up to 104MB/sec and a UHS II up to 312MB/sec, so, already we can see that UHS II card has a large speed advantage over the older standard. The speed increase is down to the two rows of contacts found on UHS II cards, this allows data to be transferred in half duplex mode (transmitting only one way as opposed to full duplex which will transmit and receive at the same time) through both sets of contacts. Because of these two sets of contacts we have more data being sent or received at any one time compared to the architecture of the single row.

So, what does this mean for us photographers? Well actually not a lot! You see, the problem with UHS II is, since it was announced in 2011, very few manufacturers have added it to their cameras. Fuji was one of the first back in 2014 but, there are still only a handful of cameras out which will support it. Hopefully over the next few years we’ll see more cameras with UHS II compatibility, now though it seems that only the higher spec bodies are having it included (Sony A9 and Nikon D500 are two of the most recent). Where does that leave the rest of us then? There are still some advantages of using UHS II cards, they’re backwards compatible so will still work in a UHS I compatible camera. Because they tend to be more recent technology they can still speed up write times in your camera, OK, only by a few MB/sec but every little helps, right! Where they’ll really shine is transferring data from the card to a computer as long as you have a compatible UHS II card reader.

To sum up UHS II, yes is does offer speed advantages over its predecessor, yes it can be used in older cameras that are still using UHS I with some small percentage increase in performance and yes you will pay more for it, anything from £5-£35 depending on the speed of the card. The main advantage though, must be the upload speed from card to computer which will be significant over older cards, and, this is where most photographers will benefit over the next few years until it’s time to upgrade your camera.

One last note, UHS III was announced January this year (2017) aimed at 8K video, ultra-high mega pixel counts etc. it doubles the speed to an insane 624MB/sec. How fast the adoption of this standard will be is anyone’s guess, but the upside is our gear in the future is going to be a lot faster than it is now.