MappleCare Community
Reply To: [Solved] How to fix ProRes Log 4K 120fps Video Recording Dropping Frames caused by External USB-C SSD write speed cache exhaustion on iPhone 15 Pro Max 1TB
Find answers from other Apple users or start a discussion about your device.
Home › Forums › iPhone & iOS Help Desk › [Solved] How to fix ProRes Log 4K 120fps Video Recording Dropping Frames caused by External USB-C SSD write speed cache exhaustion on iPhone 15 Pro Max 1TB › Reply To: [Solved] How to fix ProRes Log 4K 120fps Video Recording Dropping Frames caused by External USB-C SSD write speed cache exhaustion on iPhone 15 Pro Max 1TB
Marcus ReedFormatting external drive as APFS or exFAT with 128KB clusters and using 10Gbps USB-C data cables.
Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:
- Format the external SSD on a Mac as APFS for optimal sequential write consistency.
- Ensure cable is rated for 10Gbps or 20Gbps (USB 3.2 Gen 2×2); in-box white charging cables are USB 2.0 (40MB/s).
- Use drives with sustained non-SLC cache write capabilities (e.g. SanDisk Extreme Pro v2 or Crucial T700 enclosures).
Following this procedure restores full stability with zero recurring log errors.