The SD memory cards met the first 20 years since their commercialization a few weeks ago and are still very necessary especially in its microSD format, the smallest and most sold of this standard that offers solutions external and removable storage For almost any device.
The microSDs spread over millions of devices, including smart phones, although there are models and manufacturers that no longer support them by increasing their internal storage capacity. Its versatility, its low cost, its capacity in a tremendously reduced size, are some of the advantages so that these solutions are present in so many devices, from cameras, tablets, computers, GPS, portable consoles and a very long etc.
And not only to use them as a data file but to run applications or even operating systems. An important standard to which today we dedicate the update of a buying guide where we select the best offers available and review those factors that users have to take into account for their acquisition.
Formats and performance in microSD
Although they may seem at first sight, not all cards are the same or compatible with all devices, which we should value at the time of purchase. The same formats as standard SD cards are those in which microSDs are divided, with the following main characteristics:
- micro SD: The oldest. They have a capacity of up to 2 Gbytes and can be used in any microSD slot.
- microSDHC: They have a capacity greater than 2 GB and up to 32 GB. It can be used on devices that support SDHC and SDXC.
- microSDXC: They are the most modern and the purchase reference provided that the device supports it because they are only compatible with SDXC hardware. Its capacity varies from 32 Gbytes to an impressive 2 Tbytes. It is the theoretical maximum of the norm, although, until now, the maximum offered by the industry are the new ones of 1 Tbyte.
When choosing the card we also have to take into account that the performance is sufficient for the use to which we will allocate it. Fortunately it is easy to distinguish based on numbers inserted in a semicircle that designate the "Class". It must come printed on all the cards we buy:
It is worth knowing that these numbers do not designate the real or maximum performance but the minimum speed in Megabytes per second than in write mode It is capable of supporting the card. Although it is not usual, it is technically possible that the maximum reading speed of a Class 2 card exceeds a Class 4. In order not to get involved, always try to choose Class 10 but also try to know the maximum reading speed. The minimum supported write speed of each class is:
- Class 2: At least 2 MBps
- Class 4: At least 4 MBps
- Class 6: At least 6 MBps
- Class 10: At least 10 MBps
Maximum Performance – Minimum
Another value to be assessed is the maximum speed that microSD can reach in data transfer. Complicates the choice of a consumer, but had to be implemented to meet the needs of new applications such as 4K recording. It is about the specification Ultra High Speed (UHS) and has two versions:
- UHS-I, with bus speeds of up to 104 Mbps
- UHS-II with bus speeds of up to 312 Mbps
This data defines the maximum card reading speed and how the rest of the values must be printed on the memory cards that "I" for UHS-I or "II" for UHS-II.
Like the previous ones referred to the Class, each card that supports this format must also include printed the minimum writing speed supported, in this case the numbers 1 or 3 inserted in a U, as you will see in the image:
As for the minimum speed in writing is the following:
- U1: At least 10 MBps
- U3: At least 30 MBps
The last novelty to know in this section is the norm microSD A2, which offers a great performance jump especially at random speeds. The microSD A2 are certified with the App Performance 2 specification and use the UHS-I bus. Random speeds do not offer a significant improvement over A1, but in sequential readings / writes, which should significantly improve the use of applications in the devices where they are included.
Their main advantage over the “A1” standard is that they quadruple the minimum in random readings / writes (4,000 / 2,000 IOPS) and offer data transfers of up to 100 Mbytes per second. They are sold in several capacities, from 32 Gbytes to versions with 1 Tbyte.
To know more: nominal and relative speed
Most manufacturers cite the maximum speed in read mode that their cards are capable of reaching. The speeds are based on internal tests of the manufacturer so in most cases in real test they will be somewhat more discreet. Still it can serve as a reference. It is indicated in MB / s and it is indicated in the advertisement of the card, in the technical manual of the card or in the card envelope.
Finally, point out the "relative speed." Years ago some manufacturers used the original transfer speed in formats such as the CD (150 KBps) and some microSD providers used it to show the speed of the card. Thus, we could see something like "2x", 4x "and so on. A "100x" would correspond to a speed of 15 MBps. Except Lexar, they are not usually used, but in case you run into someone you know what is going on. It is not mandatory to use this speed data as it is to indicate the format and the class we saw above.
The future of microSD passes through SD Express
The great novelty for the future of microSD was announced last summer and is called SD Express, a new standard that will take external and removable cards to another level in performance and capacity. The new version, SD Express (SD 7.0 standard), hopes to raise the standard to a new level using the PCIe 3.0 interface and the NVMe v1.3 protocol, which are used by other storage products such as SSDs. Under PCIe, an SD Express will achieve superlative data transfer throughput of up to 985 Mbytes per second in read mode.
In addition, the maximum storage capacity on SD memory cards grows from 2TB with SDXC at 128 Tbytes that you can offer as a maximum capacity the new SD Express Ultra Capacity (SDUC). The new SD Express cards will initially be offered in SDUC, SDXC and SDHC formats. They are already being tested by manufacturers, but we still do not know release date, models and prices.
What memory card do I buy?
As always, it will depend on your needs. In Storage capacity, the current minimum for any user should be 16 Gbytes. Do not buy anything lower if your device supports it because it is not worth the price. In addition, they tend to be slower. From there, for consumption, there are models with 16, 32, 64, 128 or 512 Gbytes.
The great novelty of the last months has been the arrival of the new models of 1 Tbyte. An impressive capacity for such a small size, but forcing you to pay an extra price. Even amateur or professional photographers who may need such a large capacity, prefer to buy several cards of smaller size that apart from the cost allow to safeguard a part of the shots in case of failure of the unit. There are models available from various manufacturers such as Lexar, SanDisk, WD or Micron.
As for the performance, it will depend a lot on the device where you use it. It has nothing to do with its use in a GPS where we need to extend the storage and little else, than if we use it to run applications from it or in a camera for video recording that demands the fastest cards in the market. We always use the following Panasonic image because it is a good guide to the needs for 4K video in consumption.
Finally, point out the group of resistant microSD. Especially dedicated to professionals or users who need high durability memory cards, there are some specialized series to offer maximum resistance, protection against water, dust or X-rays of airports, in addition to including data recovery software.
Offer microSD cards (February 2020)
All major brands specializing in external and removable storage offer high reliability, speeds above the minimum established and good support, up to a lifetime warranty on the best models. Almost all of them usually include an adapter for use in SD slots like those we have on personal computers. And they can even be connected to USB ports with the corresponding adapter.
Like other solutions that depend on NAND flash drives such as SSDs, these microSD have dropped in price in the last semester of 2019 and the truth is that today they have a price available to all users up to 256 GB capacities. The trend is expected to change in 2020. If you have to buy, don't expect too much. The offer is very wide and varies according to performance and capacity. We select the most representative series of the segment, the main manufacturers and the most used capacities in the consumer market.
Capacity up to 64 GB
- SanDisk Ultra 16 GB – microSDHC card, read speed up to 98 MB / s, Class 10, U1 and A1, for 6 euros. With SD adapter and extra reader option.
- SanDisk Ultra 32 GB – microSDHC card, read speed up to 98 MB / s, Class 10, U1 and A1, for 6 euros. With SD adapter and extra reader option.
- SanDisk Ultra 64 GB – microSDXC card, read speed up to 100 MB / s, Class 10, U1 and A1, for 12 euros. With SD adapter and extra reader option.
- Samsung Evo 32 GB – Card micro SDHC, UHS -I Grade 1, Class 10, with SD adapter, for 14 euros.
- Samsung Evo 64 GB – Card micro SDHC, UHS -I Grade 1, Class 10, with SD adapter, for 26 euros.
- Samsung Pro Endurance 32 GB – Micro SDHC, UHS-I, resistant, for 18 euros.
- Samsung Pro Endurance 64 GB – Micro SDHC, UHS-I, rugged, for 27 euros.
- Kingston SDC10G2 / 16 GB – microSD memory card, 16 GB, class 10 UHS-I, 45 MB / s, black, for 6 euros.
- Kingston SDCA3 32 GB – USD-I U3 microSDHC / SDXC memory card, 90R / 80 W, SDCA3, for 11 euros.
- Kingston SDCA3 64 GB – USD-I U3 microSDHC / SDXC memory card, 90R / 80 W, SDCA3, for 11 euros.
- Kingston microSD High Endurance 64 GB – Resistant with UHS-I U1, Class: A1, U1, for 17 euros.
- Toshiba EXCERIA M302-EA 16 GB – MicroSDXC UHS-I Class 10 memory card, for 18 euros.
- Toshiba EXCERIA M302-EA 32 GB – MicroSDXC UHS-I Class 10 memory card, for 15 euros.
- Toshiba EXCERIA M302-EA 64 GB – MicroSDXC UHS-I Class 10 memory card, for 23 euros.
- Lexar 16 GB – 300x microSDHC / microSDXC 16 GB, UHS-I, for 13 euros.
- Lexar 32 GB – 300x microSDHC / microSDXC 32 GB, UHS-I, for 17 euros.
- Transcend SDC300S 32 GB – SDHC – U1 for 8 euros.
- Transcend SDC300S 64 GB – SDXC – U3 for 13 euros.
Capacity up to 256 GB
- SanDisk Ultra 128 GB – microSDXC card with SD adapter, read speed up to 100 MB / s, Class 10, U1 and A1, for 19 euros.
- SanDisk Ultra 256 GB – microSDXC card with SD adapter, read speed up to 100 MB / s, Class 10, U1 and A1, for 44 euros.
- Samsung Evo 128 GB – Card micro SDHC, UHS -I Grade 1, Class 10, with SD adapter, for 33 euros.
- SanDisk Extreme 128 GB – microSDXC card with adapter SD, A2, up to 160 MB / s, Class 10, U3 and V30, for 23 euros.
- SanDisk Extreme 256 GB – microSDXC card with adapter SD, A2, up to 160 MB / s, Class 10, U3 and V30, for 84 euros.
- Samsung Evo Plus 128 GB – Card micro SDHC, UHS -I Grade 1, Class 10, with SD adapter, for 20 euros.
- Samsung Evo Plus 256 GB – Card micro SDHC, UHS -I Grade 1, Class 10, up to 95 MB / s, with SD adapter, for 46 euros.
- Kingston SDCA3 128 GB – USD-I U3 microSDHC / SDXC memory card, 90R / 80 W, SDCA3, for 54 euros.
- Kingston microSD High Endurance 128 GB – Resistant with UHS-I U1, Class: A1, U1, for 14 euros.
- Kingston SDCR / 256GB – USD-I USD-I microSDXC Card, up to 100 MB / s in reading, for 54 euros.
- Toshiba EXCERIA M302-EA 128 GB – MicroSDXC UHS-I Class 10 memory card, for 27 euros.
- Transcend SDC300S 128 GB – SDXC – U3 for 18 euros.
- Transcend SDC300S 256 GB – SDXC – U3 for 37 euros.
- Lexar Professional PRO 128 GB – 1000x memory card, microSDXC UHS-II (USB 3.0 with adapter, includes card reader), for 71 euros.
- Lexar Professional PRO 256 GB – 1000x memory card, microSDXC UHS-II (USB 3.0 with adapter, includes card reader), for 125 euros.
- Kingston Canvas 512 GB – microSDXC card with SD adapter, read speed up to 100 MB / s, Class 10, U3, for 121 euros.
- SanDisk Ultra 400 GB – microSDXC card with SD adapter, read speed up to 100 MB / s, Class 10, U1 and A1, for 76 euros.
- SanDisk Ultra 512 GB – microSDXC card with SD adapter, read speed up to 100 MB / s, Class 10, U1 and A1, for 109 euros.
- SanDisk Extreme 400 GB – microSDXC card with adapter SD, A2, up to 160 MB / s, Class 10, U3 and V30, for 113 euros.
- SanDisk Extreme 512 GB – microSDXC card with adapter SD, A2, up to 160 MB / s, Class 10, U3 and V30, for 156 euros.
- SanDisk Extreme 1 TB – SD adapter, up to 160 MB / s, UHS Speed Class 3 (U3), V30, A2, for 402 euros.
- Transcend SDC300S 512 GB – SDXC – U3 – Class 10 – Read up to 95 MB / s, for 78 euros.
- Samsung Memory MB-MC512GAEU 512 GB, class 10 UHS-I for 89 euros.
- Lexar 633x 512 GB – microSDXC – UHS-I, Class 10, UHS-I, 100 MB / s, for 105 euros.