One theoretical benefit is that linux won't evict file data from a ramdisk, but it will evict it from cache and buffers if it thinks they are not needed that mu

One theoretical benefit is that linux won't evict file data from a ramdisk, but it will evict it from cache and buffers if it thinks they are not needed that much. The kernel algorithms for memory management are very opaque and linux may do some suboptimal decisions, especially when applications are starving for memory.