Unlike in MAX and jMax, it's not possible make PureData individually address more than 16Mfloats (64Mbytes), because beyond 24-bit the float format loses detail (no odd numbers anymore, etc.) whereas MAX and jMax have a 32-bit signed integer type which can address up to 2Gfloats (8Gbytes).
are you sure about 8GB? afaik the size limit to .wav is 2GB. thats why wav64 was introduced..
i dont suppose someone has a sox oneliner to recursively convert subdirs containing .w64 files into something pd can read? just realized how many of these files have accumulated, what with timemachine using it as the default format..