When you’re in the middle of capturing fast-moving subjects—whether it’s a sprinter crossing the finish line or a bird in mid-flight—every second counts. For photographers working in action, sports, or wildlife photography, the ability to shoot continuously without interruption is essential to getting the shot. However, one often-overlooked factor that can make or break those critical moments is the write speed of your memory card.
Understanding the impact of write speeds in continuous shooting is critical for photographers whose success depends on capturing fast-paced and unpredictable movements or nailing a perfect frame in a fleeting moment. In this article, we’ll explain memory card write speeds in detail and why choosing the right memory card is vital for capturing high-pressure moments accurately and consistently.
Understanding Memory Card Write Speeds
The write speed of a memory card refers to how fast data can be transferred from your camera to the memory card. In other words, write speed directly influences how quickly your camera can store images on a memory card. The faster the write speed, the quicker your camera can store images, and vice versa. Write speeds are measured in megabytes per second (MB/s).
It’s important to distinguish write speeds from read speeds, which refer to how quickly data can be retrieved from the card during the transfer process to a computer or external disk. While read speed affects your workflow by determining how long it takes to offload your photos, it doesn’t influence your camera’s ability to shoot continuously.
For that reason, prioritizing write speeds is essential for photographers involved in action, sports, or wildlife photography. It ensures that the camera’s performance matches the pace of the moment, allowing you to focus on capturing the perfect shot without worrying about technical limitations.
The Role of Write Speeds in Continuous Shooting
In continuous shooting mode, where every millisecond can make a difference, the write speed of your memory card plays a pivotal role in determining how smoothly your camera performs. Faster write speeds allow your camera to clear its buffer quickly, which means you can take more photos in rapid succession without interruption. This is particularly critical in situations where missing even a fraction of a second could mean losing the perfect shot—whether it’s a fast-moving athlete, a sudden wildlife interaction, or an intense moment in a live event.
When shooting continuously, your camera’s buffer acts as temporary storage. As you take a series of images, the data first accumulates in the buffer before being written to the memory card. If your memory card has a high write speed, the buffer clears faster, allowing your camera to keep shooting at its maximum burst rate. Conversely, if the write speed is too slow, the buffer fills up, and the camera has to pause shooting to catch up, increasing the likelihood of missing critical moments.
For photographers who rely on speed, like sports, action, or wildlife photographers, faster write speeds make all the difference. A high-performance memory card ensures that your camera’s burst mode operates at full capacity, giving you the flexibility to capture a series of rapid shots without interruption. This not only increases your chances of capturing the perfect frame but also provides more options when selecting the best shot from a sequence of rapid-fire images.
Factors Affecting Memory Card Write Speeds
Several factors determine how quickly data can be stored on a card, and understanding these technical aspects can help you maximize performance in continuous shooting. Let’s break down the key elements that influence write speeds:
1. Memory Card Technology
Even within the same category of memory cards, such as SD or CFexpress, write speeds can vary significantly due to internal architecture, technology used, and design differences.
For example, SD cards can differ significantly in performance due to elements such as the BUS connection type. Cards with UHS-II BUS technology feature an additional row of connectors, enabling faster data transfer than UHS-I cards. This allows UHS-II cards to handle larger amounts of data more efficiently, resulting in faster write speeds.
Similarly, while CFexpress Type B cards all use the same PCIe interface with two lanes, their write speeds can still differ due to factors like the quality of the internal components, including the NAND flash memory type and the controller used. Higher-quality NAND and more advanced controllers enable faster data handling, even when comparing CFexpress cards with the same form factor or speed class.
2. Camera’s Buffer Capacity
The camera’s buffer is a temporary storage area that holds data before transferring it to the memory card. Cameras with larger buffer capacities can handle more data during continuous shooting, but even the most advanced buffers will slow down if the memory card cannot write data quickly enough. The smaller the buffer, the faster the memory card you need to clear it timely, ensuring you can continue shooting without interruption.
3. File Type and Size
The size and type of the files you capture directly affect write speeds. Shooting in high-resolution RAW format generates large files that require higher write speeds to store efficiently. For example, RAW files range anywhere from 20 MB to 100 MB, while JPEGs average around 5 MB to 15 MB, which means RAW files require more bandwidth to be transferred to the memory card. Naturally, faster cards can handle these larger files more easily, preventing the buffer from filling up too quickly and avoiding pauses in shooting.
Choosing the Right Memory Card for Continuous Shooting
When selecting a memory card for continuous shooting, it’s essential to focus on sustained write speed rather than just peak write speed. Cards with proper ratings ensure that the card can maintain the necessary write speeds during extended bursts of shooting. For this reason, Video Speed Class ratings and VPG (Video Performance Guarantee) ratings are the most reliable indicators of a card’s ability to handle continuous shooting.
Choosing SD Cards (Video Speed Class Ratings)
Regarding SD cards, the Video Speed Class rating is essential for continuous shooting performance. These ratings, denoted on a card as V30, V60, or V90, indicate a guaranteed minimum sustained write speed in megabytes per second (MB/s).
V30 guarantees a sustained write speed of at least 30MB/s, V60 guarantees at least 60MB/s, and V90 cards are guaranteed not to drop below 90MB/s, no matter the shooting conditions.
For continuous shooting, V60 and V90 cards are the best choice, especially if you work with RAW files. These ratings ensure that the memory card can keep up with the data being generated by your camera without dropping frames or filling the buffer.
Recommendation: ProGrade Digital SDXC UHS-II V60 Memory Card – Ideal for sports, action, and wildlife photographers needing reliable, fast write speeds for burst shooting.
Recommendation: ProGrade Digital SDXC UHS-II V90 Memory Card – Best suited for professionals who require top-tier performance in demanding situations, such as intense shooting sessions involving large RAW file bursts.
Choosing CFexpress and CFast Cards (VPG Ratings)
For CFexpress and CFast cards, the Video Performance Guarantee (VPG) rating is what you should look for. VPG ratings are specifically designed for professional video and photography workflows, ensuring that the card can handle sustained write speeds necessary for video recording and fast continuous shooting.
VPG ratings are denoted on a card with a number inside a little clapper icon. Similarly to Video Speed Class ratings, the number indicates the minimum sustained write speed a card is certified to sustain. So, a VPG-200 guarantees a sustained write speed of at least 200MB/s, while a VPG-400 ensures 400MB/s.
Since VPG ratings are capped at 400MB/s, ProGrade Digital goes a step further by displaying actual sustained write speeds on our CFexpress cards rather than just peak write speeds. Peak write speeds are typically indicated with a “W” followed by a number, while our sustained write speeds are clearly marked with “Sus. W:” and the corresponding speed. For example, the ProGrade Digital CFexpress Type B Iridium card has a VPG-400 rating, but its actual sustained write speed is 850MB/s for the 400GB card and 1,500MB/s for the higher capacity cards, ensuring optimal performance during continuous, high-demand shooting.
Recommendation for CFexpress Type A: ProGrade Digital CFexpress™ Type A 4.0 Memory Card (Iridium) – With a sustained write speed of 800MB/s (480GB card) to 1,450MB/s (960GB card), Iridium Type A is a next-generation memory card utilizing PCIe Gen 4 interconnect with NVMe host controller interface for those using high-speed cameras that need top-notch performance in burst shooting.
Recommendation for CFexpress Type B: ProGrade Digital CFexpress™ Type B 4.0 Memory Card (Iridium) – With sustained write speeds ranging from 850MB/s to 1500MB/s, every professional can find a perfect card for their exact needs.
Recommendation for CFast: ProGrade Digital CFast™ 2.0 Cobalt Memory Card – With it’s VPG-130 rating, these cards are ideal for high-speed photography in demanding professional environments.
Tips to Improve Continuous Shooting Performance
To get the most out of your camera’s continuous shooting mode, it’s not just about having the right memory card—it’s about fine-tuning your entire setup to ensure optimal performance. Here are practical tips to help you maximize your continuous shooting potential:
1. Optimize Your Camera Settings
Your camera settings can greatly affect how efficiently it handles continuous shooting. Knowing your camera inside and out and adjusting its settings accordingly can greatly help improve continuous shooting performance. Here’s one universal recommendation: use a faster shutter speed. In fast-paced environments, a quicker shutter speed not only captures the moment better but also allows your camera to process and store the data faster, minimizing the buffer fill rate.
2. Shoot in Short Bursts
Instead of holding down the shutter for extended periods, use shorter bursts to allow your camera’s buffer to clear. This technique helps maintain camera performance, especially with larger file types like RAW.
3. Leverage the Camera Buffer Capacity
Your camera’s buffer capacity plays a vital role in continuous shooting. Even with a fast memory card, managing how the buffer is used can enhance performance:
- Pre-buffering: Some cameras offer a pre-buffering option, allowing you to start storing images even before you fully press the shutter button. This can help capture key moments without overloading the camera’s memory system.
- Regularly Clear the Buffer: Avoid letting the buffer fill up completely. Take periodic pauses between long bursts to allow the buffer to clear and prevent any delays in capturing the next series of shots.
4. Update Firmware
Keep your camera and memory cards updated with the latest firmware. Firmware updates can optimize performance, improve handling of large data, and ensure compatibility with new memory cards.
5. Maintain Your Cards Properly
Use free tools like ProGrade Digital’s Refresh Pro to monitor card health and reset the card’s memory cells to a factory-new state before important burst shoots, ensuring peak performance in high-pressure situations.
6. Monitor Camera’s Temperature and Battery Life
Excessive heat or low battery life can slow down your camera’s performance, including its ability to write data to the memory card. Be mindful of your camera’s temperature and keep spare batteries on hand to avoid reduced efficiency during critical moments.
Final Words: Write Speeds in Continuous Shooting
Mastering write speeds and choosing the right memory card lets you focus on what truly matters—capturing the perfect moment. With the right tools in hand, you’re not just keeping up with the action; you’re staying ahead of it, ready for every shot, no matter how fast or fleeting. Trust your gear, push your limits, and let your creativity shine through—uninterrupted.
