I really like this size of model because, on a machine with 32 GB or more of RAM (mine has 128 GB), it leaves plenty of space for running other applications at the same time.
The author endorses this model size for its modest footprint: on machines with 32 GB+ RAM, including his 128 GB setup, it leaves ample room to run other apps concurrently.
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Simon Willison: I really like this size of model, because if a machine has 32 GB of RAM or more (mine has 128GB) it leaves plenty of space for running other applications at the same time.