Our review sample IronWolf Pro 20TB was supplied to us without any retail packaging. The IronWolf Pro 20TB is built on a standard 3.5in format but with a thickness of 26.11mm. The drive has a spindle speed of 7,200rpm and there is 256MB of cache.
The drive uses Helium technology which enables Seagate to cram ten 2TB CMR platters (with an areal density of 1146Gb/in²) and 20 heads into the drive. Seagate is using TDMR (Two-Dimensional Magnetic Recording) technology in the 20TB IronWolf Pro. TDMR uses two read elements in the drive head to improve tracking accuracy which is needed as tracks are getting ever narrower as the areal density of platters increases.