The demo is doing a setBindGroup per triangle, so not exactly surprising since this is a well known bottleneck (Chrome's implementation is better optimized but

The demo is doing a setBindGroup per triangle, so not exactly surprising since this is a well known bottleneck (Chrome's implementation is better optimized but even there setBindGroup is a surprisingly slow call). But since both implementations run on top of Metal there's no reason why Safari couldn't get at least to the same performance as Chrome.