4K video refers to ultra high definition video with a resolution of 3840 x 2160 pixels. Shooting video in 4K provides incredibly detailed and sharp footage, but also requires a high data transfer speed to record all of that visual information. This is where the V30 specification comes in – it indicates that a memory card has been tested to maintain a minimum write speed of 30 MB/s when recording video.
For seamless 4K video recording, particularly at higher frame rates, a memory card needs to be able to sustain fast write speeds without slowing down or causing recording to stop. That’s why V30 speed rating is important if you want reliable performance when shooting 4K footage. The V30 mark ensures the memory card has passed a performance test for high bitrate 4K video capture.
Storage Speed Requirements for 4K
4K video has much higher bitrates and file sizes compared to lower resolutions like 1080p. A typical bitrate for 4K video is around 100 Mbps, though it can range from 50 Mbps to over 200 Mbps depending on factors like frame rate and compression. To record 4K video without dropping frames, your memory card needs to have write speeds fast enough to keep up with these high bitrates.
Most experts recommend a minimum write speed of 60 MB/s for smooth 4K recording, though 90-95 MB/s is ideal. At 60 MB/s, the card should be able to record 4K video at typical bitrates without frame drops. However, any dips in write speed can cause recording issues. With 90-95 MB/s cards, there is more headroom to account for those drops.
For higher frame rates like 4K 60fps, write speeds of 100 MB/s or more are recommended. At 60 fps, each second of footage occupies 50% more storage space compared to 30 fps. To reliably record at 60 fps, a faster minimum write speed is needed.
Overall, V30 certification or faster is recommended for 4K recording. V30 guarantees minimum sequential write speeds of 30 MB/s, though most V30 cards exceed this in real-world use. More importantly, V30 signifies support for advanced video applications like high bitrate 4K recording. While V30 is sufficient in many cases, UHS Speed Class 3 (U3) cards rated at V60 or V90 offer more headroom for flawless 4K video capture.
What is V30 Certification?
V30 is a speed class rating for SD and microSD cards that indicates a minimum sustained write speed of 30 MB/s. It was introduced in 2016 by the SD Association as part of the Video Speed Class ratings to support high resolution video recording.
The V30 rating means that a card is guaranteed to sustain transfer speeds of at least 30 MB/s when recording video. This enables smooth 4K and Full HD video capture without dropping frames or slowing down, even for extended periods of recording. Lower speed cards may struggle with high bitrate 4K footage.
Compared to older speed ratings like Class 10, V30 certifies much higher real-world write speeds. While Class 10 only requires 10 MB/s writes, V30 exceeds that by 3x at 30 MB/s minimum. This substantial speed boost makes V30 cards better suited for demanding apps like 4K video, burst photo shooting, and fast file transfers.
Real-World V30 Performance
While V30 certification indicates a minimum sustained write speed of 30MB/s, real-world testing shows there can be variation in performance across different V30-rated cards and usage conditions.
According to benchmarks on Pidramble, a SanDisk Extreme 64GB V30 A2 card scored 43.73 MB/s write speed in the 4K random write test. However, a benchmark of a Lexar 128GB V30 A2 card on the same site showed only 23.67 MB/s 4K random write speed, illustrating the range in real-world performance.
In a Reddit thread, users of the Panasonic GH6 camera found that V30 cards worked for 4K 60fps recording, but couldn’t sustain the required minimum 37.5MB/s write speed for 4K 120fps without dropping frames. This indicates 4K video at higher frame rates may require an even faster V60/V90 card.
While most V30 cards can handle 4K recording at typical frame rates, their speed consistency over longer recording times can vary. Factors like card brand, capacity, and age can affect sustained performance. Testing your specific card with your camera can help determine if the V30 rating delivers reliable real-world speeds.
When V30 May Not Be Enough
While V30 is generally sufficient for basic 4K video recording, there are some cases where even higher write speeds may be necessary:
Recording 4K at high frame rates like 60fps or 120fps generates huge amounts of data that can overwhelm a V30 card. According to Kingston, a V60 or V90 rated card would be better for capturing high frame rate 4K footage smoothly.
Shooting 4K video at very high bitrates exceeding 100Mbps is another scenario where V30 may not sustain consistent performance. As explained by ProGrade Digital, high bitrate 4K needs write speeds of at least 45MB/s sustained, so a V60 or V90 would provide more headroom.
Using lower speed cards like U1 or V10 certified cards for 4K recording often results in frustration. The slower write speeds cause recording to stop unexpectedly or lead to dropped frames and quality issues. Sticking with at least V30-rated cards ensures a minimum level of performance for smooth 4K video capture.
Maximizing 4K Recording Performance
To achieve optimal 4K video quality, there are a few key settings you’ll want to adjust in your recording software and device settings:
First, make sure you are using a video recording app capable of 4K capture. Software like OBS Studio, Open Broadcaster Software, is commonly used for 4K recording. You’ll also need a capable camera – many late model smartphones and DSLR/mirrorless cameras can record 4K.
In your recording software, aim for 4K resolution at 30 fps. While 60 fps is preferred for smooth playback, 4K60 recording requires a ton of processing power and may result in choppy footage if your device can’t keep up.
Use a high bitrate setting of 80-100 Mbps for 4K30 recording. This preserves video quality and minimizes compression artifacts. You may need to adjust based on your hardware capabilities.
Make sure chroma subsampling is set to 4:2:0 instead of 4:2:2 or 4:4:4, as this reduces file size with minimal impact on 4K image quality.
Use a constant rate factor (CRF) of around 18-22 for optimal quality, or opt for a high-quality preset like “Lossless” in your encoder settings.
Recording to an external SSD via Thunderbolt 3 or USB 3.2 Gen 2 will ensure maximum disk write speeds necessary for smooth 4K capture.
Close other programs during recording to dedicate processing power to video encoding and writing large files to disk.
By optimizing these encoding settings and recording hardware setup, you can achieve stunning 4K video quality with smooth playback and minimal compression artifacts.
V30 Alternatives for 4K Recording
While V30 SD cards provide sufficient performance for basic 4K recording, there are faster specifications available that may offer advantages for more demanding use cases. Two key alternatives are:
V60 SD Cards
V60 SD cards have a minimum sequential write speed of 60MB/s, doubling the 30MB/s speed of V30 cards. This extra bandwidth gives more headroom for high bitrate 4K video. Specifically, V60 cards can easily handle bitrates up to around 400Mbps [1].
The benefits of V60 mainly apply to very high frame rate or bit depth 4K recording. For example, 4K at 120fps or 4K with 4:2:2 color sampling. V60 cards are also more suitable for workflows involving a lot of short burst shooting.
However, for basic 4K at 24/30fps, a V60 card may be overkill. The extra cost may not justify the benefit.
V90 SD Cards
V90 SD cards push speeds even higher, with a minimum 90MB/s sequential write speed. These cards can handle up to around 650Mbps bitrates [2].
The advantages of V90 are similar to V60, but with an even greater bandwidth ceiling. This makes V90 cards ideal for the most demanding 4K recording use cases like 8K video or very high frame rate 4K.
However, like V60, V90 cards carry a price premium that may exceed the needs of basic 4K recording. For most users, V60 or even V30 cards will be perfectly sufficient.
Bottom Line on V30 and 4K
In summary, V30 SD cards usually provide sufficient write speeds for basic 4K video recording at 30fps or lower frame rates. However, V30 cards may struggle with higher bitrate 4K formats or 4K at 60fps. While real-world performance can vary between specific V30 cards, most are able to handle basic 4K video recording without issue.
For 4K recording at 60fps or higher frame rates, V60 or V90 cards are recommended to ensure maximum performance. The same applies to very high bitrate 4K formats like 4K All-I. In these situations, a V30 card may not reliably keep up with the data bandwidth required.
That said, careful testing is always advisable when selecting SD cards for important video work. Even between cards of the same speed class, real-world write speeds can differ. Checking your camera manufacturer’s recommendations is also wise. While a V30 card is usually sufficient for casual 4K shooting, pros or enthusiasts doing more demanding 4K work should consider stepping up to a V60 or V90 for extra headroom.
Frequently Asked Questions
Here are some common questions about using V30 SD cards for 4K video recording:
Is a V30 card required for 4K video?
No, a V30 rating is not an absolute requirement for 4K recording. Many cameras can record 4K video with slower cards like U3 or V10. However, a V30 card is recommended for optimal 4K performance.
What frame rates can a V30 card handle in 4K?
A V30 SD card can reliably handle 4K recording at standard frame rates up to 30 fps. For higher frame rates like 60fps or 120fps in 4K, a faster V60 or V90 card is recommended (Source).
Is a V30 card overkill for my device?
V30 cards provide minimum write speeds of 30MB/s, which is overkill for many non-4K devices. However, they still work reliably. The extra speed also provides headroom for future 4K upgrades.
What’s the difference between V30 and U3?
Both indicate minimum sequential write speeds for full HD video recording. However, V30 guarantees 30MB/s speeds compared to just 10MB/s for U3 (Source).
Should I buy V30 or V60/V90 for 4K?
V30 is sufficient for most 4K use cases. V60 or V90 is only needed for high frame rate 4K or 8K recording. V30 cards tend to be cheaper than V60/V90 cards.
Conclusion
To recap the main points, V30 is a certification for SD cards and microSD cards that guarantees a minimum of 30 MB/s sustained write speed. This makes V30 cards fast enough for recording 4K video in many situations. However, the actual write speed can vary between different V30 cards, and for high bitrate 4K recording you may need an even faster card to avoid dropped frames and video corruption.
The bottom line is that V30 is a good baseline for 4K recording, but consider your camera’s specific bitrate requirements and do your research to find a card that benchmarks at higher speeds if needed. Pay attention to real-world sustained speeds, not just manufacturer claims. And test your card’s performance before a major shoot to check if it can handle the video resolution and bitrate you plan to use without slowing down.
With the right card for your camera and settings, V30 can absolutely provide the speed you need. But it’s not guaranteed, so do your homework to find a V30 or even faster card that delivers consistent real-world performance for 4K recording.