"Too slow for its memory usage" means that that in order to use large amounts of memory, it becomes impractically slow. One of the non-finalists (Centrifuge) w

"Too slow for its memory usage" means that that in order to use large amounts of memory, it becomes impractically slow. One of the non-finalists (Centrifuge) was criticised for byte-grained random memory accesses. A random access to main memory causes a row activation delay of roughly 50ns, so one should access many nearby bytes to make up for that.