To record video in 4K or UHD resolution you need a good, fast and reliable memory card, and that is what we are going to analyze in this article: the best micro SD memory cards for 4K.
The best memory cards for 4K 🎬💾
It is evident that in today's audiovisual world, memory cards have surpassed film as the main recording medium, both in the personal and amateur sphere as well as in professional use in photography and video. The latter has always been one of the most complex tasks for a memory card, and it is due to the large amount of constant data that it has to handle.
What are the characteristics of a good SD or micro SD memory card to record 4K?
Although I have titled the article "memory cards for 4K" It really doesn't matter what resolution you are going to record at to choose a memory card. The most important thing to know before choosing a memory card for video is he BITRATE where you are going to work Knowing this information, we can know if a card is recommended or not.
What is 4K video?
When we talk about 4K video, we shouldn't really be referring to a specific screen size or resolution, since the term 4K itself mainly refers to two video formats.
These two types of 4K video differ in aspect ratio and horizontal resolution, while the vertical resolution remains the same (2160p). Let's see the differences:
DCI 4K Video
On the one hand we have the DCI 4K which is the standard for cinema, it has a resolution of 4096×2160 pixels (approximately 8.8 megapixels) and therefore a ratio of 17:9.
4K UHD video
4K UHD (Ultra High Definition) video is the standard used in home televisions and camcorders, it has a resolution of 3840×2160 pixels (approximately 8.3 megapixels) and a 16:9 ratio.
What is bitrate?
In a nutshell, bitrate is a data rate that defines the number of bits that are transmitted per second through a digital transmission systemin this case from the camera to the memory card.
The bitrate of a 4K video it is much higher than that of a Full HD video, so in order not to suffer cuts in the recording or loss of data, it is necessary to use fast and reliable memory cards. The higher the bitrate of a video, the more quality it will have and the more the files will weigh.
The bitrate is one of the measures that determines the quality of a video, although not only the bitrate is important, since the recording codec that we use (in addition to the sensor, optics, etc.) will greatly influence the final quality.
In the following table I leave you a summary of how the bitrate of a video is usually depending on its resolution and the frame rate or fps (frames per second).
But keep in mind one thing, the bitrate is expressed in mbps (megabits per second), however, the transfer speed of memory cards is usually expressed in MB/s (megabytes per second). This change of units often becomes confusing.
The conversion between both units is as follows:
- 1 byte = 8 bits
For example, an action camera GoPro that records video in 4K at a bitrate of 150 mbps you need a memory card that is capable of recording data at a stable speed of 18.75 MB/s (150/8=18.75).
Now you know how to calculate the minimum speed you need to record video in any resolution, just knowing the bitrate of your camera!
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Tips before buying a microSD for 4K
It is very important to choose the memory card to record video. A video camera card cannot afford to drop its performance below the recording bitrate.
Minimum or sustained speed
If this happens frames will be dropped and the recording may stop and even lose data. It is very important to look at the minimum write speed or sustained data rate.
The maximum speed or the transfer peak is not so important, as well as the sustained speed. I mean by this, it is not that useful for a card to have a peak of 150 MB/s if the sustained or average speed is not high.
Read speed vs write speed
Memory card read speeds are always higher than write speeds. Manufacturers do not usually specify write speeds and use read speed as a marketing figure, since it is always higher.
Sometimes manufacturers don't even specify the speed of their card in MB/s. There are brands like Lexar that usually express the speed of their cards in "x". This nomenclature comes from the old CD-ROM standard. If you lived through the era of transition from floppy disks to CDs, surely you remember these pictograms on CD and DVD readers and recorders.
In this digital speed standard, 1x equals 150 KB/s. To convert the speed of a card expressed in this way to MB/s, you must multiply by 150 and divide the result by 1000.
Look at the image above. This micro SD from Lexar advertises a speed of 633x. To know your speed in MB/s we multiply 633×150=94950, divide the result by 1000 and the result is 94950/1000=94.95MB/s
Micro SD recommended for 4K
Almost all the reliable brands and the main manufacturers have in their catalog a series of cards that are faster and more reliable than the others. The speed of these cards are ideal for recording high resolution video, so if you are looking to record 4K with your phone or your GoPro, for example, you have to look for a medium / high-end micro SD.
These micro SD cards, ideal for 4K video, are also perfectly valid for recording with a DSLR or video camera that supports the SD standard. Almost all micro SD are sold with the adapter to full size SD, and this way you can use it in more devices.
In the memory card buying guide we saw that there is a classification called Video Speed Class. These cards are a safe bet to save 4K video due to their characteristics.
SanDisk Micro SD for 4K video
SanDisk has two lines of Class V30 micro SD cards: SanDisk Extreme and SanDisk Extreme PRO. This V30 class It assures us a minimum stable transfer of 30MB/s.
SanDisk Extreme for 4K
With these cards you will have fast transfers and optimal performance in mobile applications (Class A2) and 4K UHD videos (Class V30) for an affordable price. They are ideal for Android smartphones, action cameras like GoPro or drones. Due to their technical characteristics, they are ideal for recording 4K UHD and Full HD videos, or taking high-resolution RAW and JPG photos, even in bursts.
They offer a maximum read speed of up to 160 MB/s and write speeds of up to 90 MB/s.
They are available in capacities of 32GB, 64GB, 128GB, 256GB, 400GB, 512GB, and 1TB.
SanDisk Extreme PRO for 4K video
The SanDisk Extreme PRO segment is focused on professional use to work with photography and 4K UHD video faster than the Extreme. They are faster and more reliable and withstand extreme environmental conditions. SanDisk Extreme PRO memory cards record smooth 4K Ultra HD UHD video with transfer speeds of up to 95MB/s.
To the Like the SanDisk Extreme, they are available in capacities of 32GB, 64GB, 128GB, 256GB, 400GB, 512GB, and 1TB.
Samsung EVO Plus for 4K video
Samsung memory cards are also suitable for recording video in 4K resolution. They have a great quality/price ratio and are ideal for use on smartphones, Nintendo Switch game consoles or action cameras such as GoPro.
The new range of cards micro SD Samsung EVO Plus for 4K It comes with a UHS-3 (U3) and Class 10 BUS controller, with which it can reach maximum speeds of 100Mb/s reading and 90 Mb/writing.
They are waterproof and can remain submerged for up to 72 hours in salt water without losing data, withstand extreme temperatures, magnetic fields and X-rays such as security arches at airport controls.
They are for sale on Amazon in 32 GB, 64 GB, 128 GB, 256 GB and 512 GB.
For more information about these cards you can take a look at this article.
Micro SD Lexar for 4K video
range of micro SD cards for 4K Lexar Professional It is the fastest of the brand. Its maximum reading speed is 1000x or what is the same, up to 150MB/s. With that transfer rate we have enough to record in 4K without problems.
They are available in versions of 32GB, 64GB, 128GB, and 256GB.
Compact Flash memory cards for 4K
Compact Flash has lost prominence in recent years and has been superseded by SD and micro SD. But today there are still video cameras and DSLRs that use these cards. Go
In the past CF cards were based on the PATA standard, an old and obsolete standard that was replaced by the current UDMA 7. This standard allows Compact Flash cards to reach read speeds of up to 167 MB/s. With these figures, they are cards fast enough for most photographic and video uses, and of course capable of recording 4K.