Problem
A high-bitrate All-I recording mode exhausts the SD card's sustained write buffer, forcing dropped frames even though the card's advertised peak speed appears adequate.
Solution
Root Cause / Diagnostic:
Camera All-Intra recording streams at sustained bitrates (e.g., 400–800 Mbps / 50–100 MB/s) with zero inter-frame compression buffer relief. Consumer SD cards advertising "300MB/s" quote peak read bursts; once internal pseudo-SLC buffers fill, write throughput collapses below the camera's required baseline, forcing frame drops or buffer overflow shutdowns.
Actionable Fix:
1. Video Speed Class Upgrades: Replace standard cards with certified Video Speed Class V90 (guaranteed 90MB/s sustained write) or transition to CFexpress Type A/B media.
2. Codec Compression Optimization: Reconfigure camera recording from All-I to Long GOP (IPB) compression (reducing bitrate demands to 100–150 Mbps) when recording to V60 or V30 media.
3. Card Low-Level Format: Perform an in-camera full low-level format before high-bitrate shoots to erase dirty flash blocks and reset write buffers.
Pro Tip:
Peak read speed printed in giant numbers on the front of an SD card is marketing; the only number that matters for video recording is the small circled "V" rating (V30 = 30MB/s, V60 = 60MB/s, V90 = 90MB/s sustained).
Camera All-Intra recording streams at sustained bitrates (e.g., 400–800 Mbps / 50–100 MB/s) with zero inter-frame compression buffer relief. Consumer SD cards advertising "300MB/s" quote peak read bursts; once internal pseudo-SLC buffers fill, write throughput collapses below the camera's required baseline, forcing frame drops or buffer overflow shutdowns.
Actionable Fix:
1. Video Speed Class Upgrades: Replace standard cards with certified Video Speed Class V90 (guaranteed 90MB/s sustained write) or transition to CFexpress Type A/B media.
2. Codec Compression Optimization: Reconfigure camera recording from All-I to Long GOP (IPB) compression (reducing bitrate demands to 100–150 Mbps) when recording to V60 or V30 media.
3. Card Low-Level Format: Perform an in-camera full low-level format before high-bitrate shoots to erase dirty flash blocks and reset write buffers.
Pro Tip:
Peak read speed printed in giant numbers on the front of an SD card is marketing; the only number that matters for video recording is the small circled "V" rating (V30 = 30MB/s, V60 = 60MB/s, V90 = 90MB/s sustained).