ZRAM if you have no HDD/SSD swap partition.
ZSWAP if you do have a HDD/SSD swap partition.
ZCACHE: It does what ZSWAP does and ALSO compresses and speeds the filesystem page cache. (It is internally much more complicated and is not in the mainline kernel as it is still under development).
R. Vijayaraghavan, and C. Sarazin. (2017)cite arxiv:1706.00021Comment: Submitted to ApJ. 23 pages, 14 figures. Animations for this paper are at this URL: https://virginia.app.box.com/v/anisotropic-conduction.