If you are looking to add memory to an MicroSD device the fasted available option is using a MicroSD UHS II type card. In this review I’ll tell you more about Toshiba’s Toshiba Exceria PRO M501 UHS II 64 GB MicroSD card. With a UHS class 3 rating this is the fastest MicroSD card Toshiba offers right now and it is perfect for devices that record 4K video or for transferring data from the MicroSD card to other devices quickly. The Toshiba Exceria PRO M501 is also extra durable so it is perfect for use in tough conditions.
UHS I, UHS II, UHS speed class 1, UHS speed class 3?
In making the difference between SD cards more easy the SD card association has chosen to use different kind of ratings as time went by and cards became faster and faster. By now there are so many different ratings, letters and numbers on a card you may get confused by them in stead of it helping you to choose the right card. In this review I’ll limit myself to the UHS-rating with the roman number and the number in the capital U. There are some older cards that have a number in ‘C’, that is an old rating system you can forget about that for now, as the new UHS rating is of better use for fast and modern SD and MicroSD cards.
Firstly, UHS vs UHS II. UHS and UHS II are the types of interface or bus. There is a difference in the connector on the card itself. UHS uses a single row of connectors. UHS II uses a double row of connectors making it possible to reach higher throughput speeds. A card with a (UHS) II label must have a minimal speed of 156 MB/s and a maximum speed of 304 MB/s. Because UHS II is fully backwards compatible to UHS you can use a UHS II card in any device that is compatible with UHS. No worries there!
Besides the roman number of the UHS-type you’ll also find a normal number written in a capital U. In the case of the Toshiba Exceria PRO M501 you’ll see it has a small 3 written on it. This is the UHS speed class. U1 means the card will offer a minimum write speed of 10 MB/s. U3 means it will do at least 30 MB/s. The cards must be able to offer these write speeds even when you are simultaneously downloading from and writing to the card.
So to wrap up, the Toshiba Exceria PRO M501 must have a speed of 156 to 304 MB/s (it does with a rated 270 MB/s read and 250 MB/s write speed) and must be able to reach a write speed of at least 30 MB/s even when downloading from the card at the same time as you are writing to it. Meaning it will be fast enough for recording high bitrate 4K video even when you are reading data from the card at the same time.
Despite the small size normal MicroSD cards are quite durable, but the Toshiba Exceria Pro can handle even tougher conditions. It is X-ray proof, waterproof, shockproof and can be used in temperatures ranging from -25 to +85 degrees Celsius. This make the Toshiba Exceria PRO M501 perfect for action sports enthusiasts that want to use the card in their action camera’s in demanding conditions or for people that will be using it in a drone. This also means that the card will stand up to any kind of abuse it will endure when you were to use it for normal video recording or photography. In that case you will never test it to its limits but it is a reassuring to know that your Toshiba Exceria PRO M501 will be able to take a lot more abuse than the device you are probably using it in.
There are still just a limited amount of devices that are compatible with MicroSD UHS II cards. Most modern smartphones, cameras, drones and other devices will only support UHS type I cards that are quite a bit slower than the Toshiba Exceria PRO M501 with its UHS II class 3 label. So, unless you have a compatible UHS II device, why would you even consider buying a more expensive UHS II card? Well, it does mean your card is ready for faster, new devices you may buy in the future. But the second, perhaps more compelling reason is that UHS II compatible USB 3.1 card readers are not expensive to buy and there are a lot of models for sale. So when you will also use your MicroSD card to transfer data to a PC that will be a lot faster than using a normal card. A UHS II class 3 is also fast enough to record 4K video while reading data from the card at the same time. So that may be of interest for people that require the absolute best performance all the time.
I’ve tested the Toshiba Exceria Pro UHS II card with a Transcend RDF9 card reader that is compatible with USB 3.1 and SD UHS II cards in the MicroSD to SD adapter that came with the card. The card reader was connected to a USB 3.0 port on my laptop. Despite the fast card reader and using a USB 3.0 port I wasn’t able to reach the full theoretical speeds, probably because the USB 3.0 port on my laptop isn’t fast enough. In theory the Toshiba Exceria Pro should be able to read with speeds of up to 270 MB per second and write with speeds of up to 250 MB per second.
In my test I’ve found I was able to download a 1 GB file at a very stable 193 MB/s. To put that in perspective, it took just over 6 seconds to download the 1 GB file, I even had to hurry to take a screenshot wile the download was in progress. Uploading from my pc to the MicroSD card the Toshiba Exceria PRO M501 reached speeds of about 120 MB/s. Uploading was also very stable so it was able to complete the whole transfer with a minimum of 120 MB/s. For comparison, recording a 4K Ultra HD video will write about 10-14 MB/s to your card (when you use a high bitrate), so a Toshiba Exceria Pro UHS II card is certainly fast enough for 4K video!
To compare those speeds with I’ve also tried the same using an older USB 3.0 UHS I compatible Transcend RDF8 card reader. When using the card at UHS I speeds I was able to download the file at about 80 MB/s. Uploading to the card the speeds where around 70 MB/s. Quite a difference from the UHS II speed! So when you regularly down- or upload large amounts of data from or to your MicroSD card with a card reader the added speed will make a big difference.
If you are looking for a extremely quick MicroSD card to add storage to you device a UHS II card may be overkill for most devices. But if you plan using it to download data to your PC via a UHS II compatible card reader or if you have an UHS II compatible device the Toshiba Exceria PRO M501 is a very good choice. Toshiba Exceria PRO M501 is a little less expensive than the Sandisk alternatives at most shops while offering very high durability for long lasting performance and giving you the same speed as the more expensive Sandisk cards. The Toshiba Exceria PRO M501 comes with a SD-adapter as standard.
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My name is Rick Roeven, I live the Netherlands. I’m an amateur photographer, tech and gadget lover and I've started this blog to share my passion with others. If you have any questions, feel free to post a reply or send me an email at rick (at) ricksreviews.org