Western Digital WD Red Pro 26 TB NAS hard disk in test – Good performance for a little too much money

1 - Introduction and technical data 2 - Power consumption 3 - Temperatures 4 - Performance: Ultra HD streaming 5 - Synthetics, summary and conclusion

The AJA System Test is an established tool in professional video and post-production, specifically designed to assess memory performance in relation to video workflows. In contrast to synthetic benchmarks such as CrystalDiskMark or ATTO, which tend to measure peak values for linear transfers, AJA simulates real data streams from typical video formats – including frame sizes, write behavior and buffer usage as they occur during capture or playback. The measurement results from the AJA test are therefore particularly relevant when it comes to the actual suitability of a drive for broadcast, editing systems or recording servers such as an OBS recorder.

The measured write and read curves of the WD Red Pro 26 TB clearly show that this drive is ideally suited for continuous video data. In the write test (“Capture”), the effective transfer rate is constantly in the range of 240 to 260 MB/s, with individual dips which, however, never fall below practically relevant thresholds. The read test (“Playback”) is just as stable, with a clearly smoothed trend curve above 250 MB/s and only marginal outliers. This smooth transfer characteristic is crucial for loss-free, error-free recording and playback of large video files. But more on this in detail in a moment.

In a professional context, it is not the maximum performance of a storage medium that is decisive, but the ability to provide a certain minimum data rate permanently without jitter or interruption. This is particularly important for formats such as ProRes, DNxHR, REDCODE RAW or uncompressed 10-bit YUV. AJA test data is the reference here because it simulates precisely these requirements. The WD Red Pro 26 TB proves in this environment that it not only works with a high sequential transfer rate, but also shows no fluctuations over time that would lead to dropped frames or capture errors. This makes it suitable not only for simple archiving tasks, but also explicitly for continuous recording of multiple UHD streams in real time. The measurement with AJA underlines that the CMR-based architecture with a large cache and stable mechanics can have a decisive advantage over consumer SSDs under long-term load.

The relevance of the AJA measurement therefore lies in its high practical relevance and the fact that data rates such as those measured here represent the boundary between a functioning production workflow and one that is at risk of failure. If you work with 4K video data and have to cope with a permanent base load of around 100-150 MB/s, the WD Red Pro 26 TB is one of the few mechanical hard disks that can carry this load not just for a short time, but permanently with stable performance. These AJA system test results document the read and write behavior of the WD Red Pro 26 TB when continuously transferring large amounts of data, as is the case with longer video recordings or playbacks. In this case, the test simulates a professional scenario with sequential access, which corresponds to typical requirements from the video or surveillance sector.

Read test (playback)

The diagram for disk reads shows a stable curve with a transient response within the first few frames. After less than 50 frames, the transfer rate stabilizes and remains between around 230 and 290 MB/s over the entire period. Although the downward outliers are recognizable, they rarely reach values below 200 MB/s and never occur with critical frequency. The average read throughput rate is well above 250 MB/s based on the visual progression, which can be rated as very good for a mechanical hard disk with CMR recording and ten platters.

Write test (Capture)

The write test shows a similar picture with a slightly higher degree of fluctuation. Here too, the average value is stable in the range of around 240 to 260 MB/s, with short-term deviations in both directions. Individual dips below 200 MB/s are visible, but never reach critical lows. The green trend line is constant, with no indication of thermal throttling or buffer overflow. It can be seen that the WD Red Pro 26 TB delivers stable write performance even with longer, sequential loading of large amounts of video data.

Comparison with a SATA SSD

Typical SATA SSDs such as a Crucial MX500 or a Samsung 870 EVO achieve sequential transfer rates of around 500 to 550 MB/s when reading and writing. In mathematical terms, this is around twice as high as the WD Red Pro 26 TB. However, the difference is not always relevant in practice, as many video applications do not require peak values, but demand a continuous minimum bandwidth. In addition, many SATA SSDs show a significant drop in the write rate during longer, uncompressed writing of large files (such as RAW video recording) as soon as the SLC cache is exhausted. This can be limited to a few minutes with QLC or TLC SSDs. In contrast, the WD Red Pro 26 TB delivers constant performance over long periods of time, which makes it particularly suitable for continuous recording.

Technical classification

Finally, I have a technically sound table for you with the typical data rates of common video formats and codecs as used in professional and semi-professional environments. This data can be set directly in relation to the sequential transfer rate of the WD Red Pro 26 TB, which was able to consistently achieve around 250 MB/s (equivalent to 2000 Mbps) in the AJA test. This shows how many simultaneous streams could theoretically be written to or read from the drive in parallel, always assuming the CPU and I/O subsystem do not limit it.

The maximum practicable transfer rate of around 250 MB/s primarily limits uncompressed or visually low-loss formats such as ProRes, DNxHR, RAW or 10-bit YUV, which require large amounts of data with short buffer times. In practice, the WD Red Pro can process 1 to 3 simultaneous streams before bottlenecks occur. This is not the case with highly compressed formats such as H.264, H.265 (HEVC) or AV1, which require significantly less bandwidth thanks to GOP structures, motion compensation and adaptive bit rate behavior. Even at 4K and 60 fps, data rates below 10 MB/s are not uncommon. The full capacity of the drive can be used effectively here. AV1, as the most modern and efficient codec, allows over 50 simultaneous streams at typical quality settings without reaching the mechanical limit of the hard disk.

In the surveillance or streaming environment with H.265 encoding in 1080p at approx. 5 Mbps (0.6 MB/s), up to 400 parallel camera streams could be recorded on the WD Red Pro 26 TB, provided that the NAS or host system has sufficient network and storage controller capacity.

Interim conclusion

The WD Red Pro 26 TB is very well suited for sequential video recording. For RAW formats and broadcast workflows, the transfer rates are sufficient for a few parallel streams, but for compressed formats for dozens to hundreds of simultaneous accesses. So if you want to store many simultaneous HEVC or AV1 streams – for example in a surveillance server, OBS recorder or archive system – this hard disk is a high-performance, long-lasting solution. Only for pure RAW workflows or real-time editing with more than 3 parallel UHD sources should you consider faster storage media such as U.2 SSDs or NVMe.