EXO Labs benchmarks put Llama 3.1 8B at 14 tok/s on an iPhone 15 Pro

EXO Labs opened a public benchmark site on December 25, 2024, as the first entry in a twelve-part series, publishing generation speed and time to first token measured on real consumer devices. EXO states these are measurements rather than estimates. In the data behind the site, an iPhone 15 Pro with 8 GB of RAM generates 14.0 tok/s on Llama 3.1 8B and takes 1.67 seconds to return its first token.

A Galaxy S24 Ultra with 12 GB manages 5.6 tok/s on the same 8B model, with 4.16 seconds to the first token, according to EXO’s published results. On the smaller Llama 3.2 1B the iPhone reaches 56.1 tok/s and the Galaxy 22.5 tok/s. A single Mac mini M4 Pro with 24 GB sits at 49.3 tok/s on Llama 3.1 8B, which puts the phone at under a third of the Mac’s rate on the same model.

EXO splits a model into contiguous slices of its layers and hands each slice to a different device, so a model too large for one machine can run across several. The activations passed from one device to the next are small, under 4 KB for Llama 3.2 3B, and EXO says the bottleneck is network latency rather than bandwidth. Pooling phones does not speed up a single reply. A cluster of two iPhone 15 Pros and one Galaxy S24 Ultra runs Llama 3.1 8B at 7.0 tok/s, below the 14.0 tok/s of one iPhone alone, which EXO attributes to network overhead when the model already fits on a single device.

Three Mac mini M4 Pros run Llama 3.3 70B at 4.1 tok/s, a model that does not fit in the 24 GB of any one of them. Every entry carries a timestamp, a git commit and the identifier of the automated run that produced it, and the site is free to browse. EXO says it is expanding the suite towards mixed device types and different quantisations, and the exo runtime itself is on GitHub under Apache 2.0.