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Apple's GPU Has No 64-bit Floats. I Made It Sort 50 Million Doubles Anyway
Data Engineering15 min read

Apple's GPU Has No 64-bit Floats. I Made It Sort 50 Million Doubles Anyway

The Metal Shading Language has no double type, and float64 is the default number in Python, pandas and Apache Arrow. Building ArrowMetal meant getting past three walls: a GPU with no 64-bit floats, a missing 64-bit atomic add, and a Swift compiler bug that reports errors nobody threw. Here is how each one was solved, what it cost, and why a GPU that cannot add two doubles sorts 50,000,000 of them in 32 ms.

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Apache Arrow Compute on the Apple Silicon GPU: The First Arrow Project I Created That Does It, With 173 Operations Measured Against Polars, pyarrow and pandas
Data Engineering11 min read

Apache Arrow Compute on the Apple Silicon GPU: The First Arrow Project I Created That Does It, With 173 Operations Measured Against Polars, pyarrow and pandas

I built ArrowMetal, the first Apache Arrow project I could find that runs compute on the Apple silicon GPU. Apple silicon has one memory for CPU and GPU, and an Arrow buffer in shared Metal memory is already a GPU buffer; no Arrow project used that. ArrowMetal does: 307 of Arrow's 307 compute functions, seven languages, take at 24.2x pyarrow on an M4 Max, and 339 benchmark rows against the fastest CPU idiom of Polars, pyarrow, pandas and numpy, including the 77 where the CPU is still ahead.

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