I'm well aware of what the major use for this library is. For my particular needs I don't even care about Java computation performance, I do almost everything with OpenCL. I just wanted to share my findings for people that may see this library and think all their performance problems are magically gone, just because there's no bounds checks with Unsafe or whatever. Since computation has to happen eventually, there may be a temptation to do it on mapped data, which may lead to the performance gotchas I described.