
WD Red SMR vs. CMR Tested - dragontamer
https://www.servethehome.com/wd-red-smr-vs-cmr-tested-avoid-red-smr/
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dragontamer
Back when the CMR vs SMR WD issue came up, a big question came up: "Will the
users ever notice the difference in technology"

For many desktop users, maybe not. But this ServeTheHome test indicates the
big issue with SMR Drives in one test: [https://www.servethehome.com/wp-
content/uploads/2020/05/SMR-...](https://www.servethehome.com/wp-
content/uploads/2020/05/SMR-RAIDZ-Rebuild-v2.png)

A RAIDZ-rebuild happens on occasion for NAS users. The CMR drives all
completed their rebuilds in 17 hours, but the SMR drive took 229 HOURS (over 9
days) to rebuild.

It is these kinds of "sustained write" workloads which NAS-users will come
across that typical desktop users won't. The poor sustained write performance
of SMR really shows in this particular use case.

