zRam increases performance by avoiding paging on disk and instead uses a compressed block device in RAM in which paging takes place until it is necessary to use the swap space on the hard disk drive
This module is enabled in Pi config file [arch/arm/configs/bcmrpi_defconfig ] CONFIG_ZRAM=m
extract from wiki : ZRam
How does it improves the performance in Pi. Please suggest any bench mark tool to verify the performance improvement in R Pi.