Logic Pro Slow Loading on M2 Ultra: The £10 Cable That Fixed It

The Client’s Challenge

I recently received an enquiry from a film trailer composer who was facing a frustrating bottleneck in his production workflow. Despite investing in a top-tier setup—a Mac Studio M2 Ultra with 192GB of RAM—his system was performing significantly below expectations.

He described the issue clearly in his initial message to Audio Support: despite his high-spec machine and samples stored on external SSDs via a Blackmagic Multidock 10G, opening a session took nearly 25 minutes. Furthermore, Logic Pro would frequently hang (displaying the “spinning rainbow wheel”) when bouncing stems, often forcing a hard restart. For a professional working on tight deadlines, losing hours to loading screens and crashes is simply not sustainable.

Diagnosis

Once I had access to the client’s Mac Studio, I needed to verify the data transfer rates. With a template reliant on heavy Kontakt libraries, the speed at which data moves from the external drive to the RAM is critical.

I opened Activity Monitor and watched the Disk tab while we attempted to load a Logic Pro project. The data confirmed the client’s suspicion: we were seeing transfer speeds of around 30 MB/s. For a modern SSD connected to an M2 Ultra, this is incredibly slow—barely scratching the surface of what the drive should be capable of.

To understand why the speed was throttled, I checked the hardware connection status. I navigated to the Apple Logo > System Settings > General > About > System Report.

Under the hardware list, I located the USB/Thunderbolt section to inspect the Blackmagic Multidock 10G. Although the device was recognised, the link speed was listed as 480 Mbps. This was the “smoking gun.” 480 Mbps is the maximum speed of the USB 2.0 protocol. Somewhere in the chain, the connection was being downgraded from the expected 10 Gbps to legacy USB 2.0 speeds.

Result

A week later, I received an email from the client. He had replaced the cable connecting the Blackmagic Multidock to the Mac Studio.

The difference was immediate. He described Logic Pro as running “20 times faster” than before. The 25-minute load times had vanished, and the system stability issues during bouncing were resolved. The Mac Studio was finally performing like the powerhouse machine he had paid for.

Reflection