If you’ve shopped for an SD card in recent years, chances are you’ve found the process needlessly baffling. In case you’re wondering, we don’t blame you for one second! Terms like ‘write speed,’ ‘video speed class,’ and ‘sequential write speed’ can all make the world of SD cards seem impenetrable to the uninitiated.

One debate seems to capture the attention of online audiences more than any other – the class 10 VS UHS speed class 1 question. Which is better for your requirements? Is it clear cut or can it depend on what you’re doing?

On this page, we’ll explore both class 10 and UHS 1 SD cards in detail. We’ll cover minimum sequential write speed, cost considerations, and much more. Read on to become an SD card pro.

Understanding Speed Classes – The SD Association

high speed UHS 1

Before we dive into the speed ratings and other details of these two SD card classes, it’s worth talking about the guys who came up with all these classifications in the first place. The SD Association has been setting universal standards for memory cards since 2000.

They provide capacity and speed ratings for practically every sd card on the market. Our top tip is that if you’re ever in doubt about which speed class is right for you, their website might be the best place to start.

It’s likely to have the most up-to-date information about write speed and other details. One frustrating fact to keep in mind is that this information is changing all the time. The ‘best’ speed class today is likely to be surpassed in just a handful of months as memory technology develops exponentially.

UHS 1 VS Class 10 – Write Speed and More

What does minimum sequential write speed mean?

Enough talk! Let’s get into each of these SD card classes and what sets them apart. A bit further down this page, we’ll also cover some of the most common terms you’re likely to encounter when shopping for SD cards online.

What’s Class 10?

The first thing to mention here is that a class 10 sd card used to be the fastest available speed class for memory cards. Since 2009, however, the faster, higher-capacity UHS speed class emerged and took over in popularity.

So, does this mean a class 10 SD card is a waste of money these days? Well, not always.

You’ll be dealing with a minimum sequential write speed of 10 MB/s so if this is enough for your requirements, a cheaper card may be ok for you. Some class 10 cards will be advertized as significantly faster than this. For example, a class 10 SD card might offer a transfer speed of ‘up to 80 MB/s.’

Pay attention to the wording here. ‘Up to’ is not the same as the speed you’re going to experience every time. The devices and SD card reader you’re using also matter a fair bit.

The thing is, if you’re using an older device, it may only work with an SD card of a similar age. The newer UHS speed class cards use an updated UHS bus that is incompatible with older devices.

This means that if you’re using an older camera or device, you may need a card that uses this original speed class.

What’s UHS 1?

Since 2009, the UHS speed class has become the standard for most cards around the world. UHS I was the first version of this new specification. As with the class 10 speed class described above, a UHS I card offers a minimum sequential write speed of 10 MB/s.

It’s important to note, however, that this doesn’t mean class 10 and UHS 1 are the same in terms of user experience. The UHS bus speed is faster than the older class 10 standard. Your maximum theoretical speeds will likely be much higher with this kind of card.

If you’re using a camera from the last few years, you’ll likely want to get either a UHS 1 or UHS 2 card – the older class 10 standard my be incompatible. In general, the UHS bus is the way to go these days.

UHS 1 VS Class 10 – The Bottom Line

While it may seem like a ‘cop out’ our advice is to check the manufacturer advice given for the specific device you need storage for. The world of SD and micro SD card types can be treacherous to navigate and it isn’t always as simple as ‘this UHS speed class is best.’

Sony cameras can have their own idiosyncrasies and Nintendo Switch owners have their own set of obstacles to navigate, for example.

Tips for Nintendo Switch Users – SD Cards

While we’re on the subject, let’s explore what to look out for when buying an SD card for your Switch. Right out of the gate, the original speed class 10 won’t be of any use here. The following micro SD card types will work on the switch:

  • microSD (up to 2 GB)
  • microSDHC (4 GB – 32 GB)
  • microSDXC (64 GB and above)

Just remember the following:

  • You’ll need to do a system update before you can use your new card
  • Only a micro SD card will work – full-size cards are too large

This information was pulled from the Nintendo US site.

Choosing the Right SD Card – Terms Explained

We hope our outline above has helped thus far. In this section, we’ll dive deeper into the different terms and concepts that are useful to understand when shopping for a new memory card.

SD Cards

So, what does ‘SD’ even stand for? The answer is ‘secure digital.’ Cards with just ‘SD’ on them and nothing else are likely from the original speed class and capacity from the early 2000s. The maximum amount of space on this kind of card is 2GB.

SDHC Cards

The ‘HC’ in ‘SDHC’ cards stands for ‘high capacity.’ This is slightly more recent classification that first emerged in 2006. An SDHC card usually offers a higher transfer speed than older cards. An SDHC card can store up to 32 GB of data.

For more casual use cases, an SDHC card may be enough. For larger files that need higher transfer speeds, however, you’ll want an SDXC card.

SDXC Cards

The ‘XC’ in SDXC stands for ‘extreme capacity.’ As the name suggests, these cards can store significantly more data – up to 2000 GB in fact! If you’re looking for the fastest transfer speeds and a bigger capacity, this is the kind of card to go for.

The trouble is, there are myriad other terms used to describe most cards on the market. The vast majority of these are for marketing purposes and shouldn’t carry as much weight when you’re shopping.

Terms like ‘extreme pro edition’ or ‘hyper drive’ can be overlooked. Worry more about things like ‘UHS 1’ or ‘SDXC.’ If in doubt, check the SD Association website for more details.

Sequential Write Speed

So, what does sequential write speed even mean? A sequential write is a type of data transfer where blocks of data are transferred to adjacent blocks in a system. For our purposes, though, this is less relevant.

The important take-away here is that sequential write speed indicates how quickly data can be transferred to a device. In this case, how quickly data can be loaded onto your memory card.

Minimum Write Speed

This one is fairly self-explanatory but we’ll touch on it briefly just in case. The minimum sequential write speed of a card is absolute slowest speed you’re likely to deal with when using it to transfer data.

In most cases, you’ll be able to get transfer speeds significantly higher than this advertized minimum. Also be sure to watch out for terms like ‘up to 100 MB/s’ when shopping. You may be able to reach this advertized max speed, but your devices and other factors can slow things down significantly.

Maximum Capacity

You guessed it, the maximum capacity of a memory card denotes the maximum amount of data it’s able to store. You may want to expect a capacity that’s slightly lower than the advertized maximum – the files you’re storing and the way that they’ve been stored can slightly alter the amount of data you’re able to save.

This is also sometimes referred to as the ‘theoretical maximum’ capacity of a memory card.

Video Speed Class

Those using high speed action cameras and similar devices will probably benefit from a video speed class card. This is a more recent class of memory card that’s able to handle the high speeds and capacities that come with video capture.

It also supports more advanced features like 360 degree video capture and multiple video streams. If this sounds like the kind of card for you, look out for the ‘V’ symbol when shopping. This starts at ‘V6’ and moves all the way up to ‘V90.’

Ultra High Speed Class VS Class 10 – Conclusion

We hope you’ve found the information above useful! Hopefully you now understand that the UHS speed class replaced the older ‘class 10’ cards in 2009. If you’re looking for a TLDR, follow this general advice:

  • Check your manufacturer’s advice if you’re unsure – they should give specific recommendations
  • Check the SD Association website for more details
  • Devices before 2009 usually need a class 10 or lower card
  • More recent devices usually need UHS 1 or higher


U3 vs U1 memory cards