About a minute or so for the batch of 64, but I haven't tuned the implementation yet (I just did enough work to get it down to a comfortable range of experiment

About a minute or so for the batch of 64, but I haven't tuned the implementation yet (I just did enough work to get it down to a comfortable range of experimentation). The paper I linked (https://eprint.iacr.org/2018/1041.pdf https://eprint.iacr.org/2018/1041.pdf) which uses the same model, but with a more optimized implementation cites 26ms amortized per image (in a batch of 64), so I would suspect I can get down to that with a day or two of optimization work if I wanted to (or just plug in their backend - but where's the fun in that).