karthikri5 years ago000What is the difference between WD40EFAX & WD40EFRX ?aftab5 years ago • purchased this product+220purchased this productWD40EFAX is the latest version of 4TB capacity and it has 256 MB cache. Whereas WD40EFRX is the previous version with 64 MB cache. WD40EFAX is faster than WD40EFRX. However, I find WD40EFAX (new version) a bit louder/noisier than the older version.Comment2 comments