Are the WDC WD30EFRX drives CMR or SMR

I can’t seem to find any reference on this or other sites as to the recording technology (SMR or CMR) of the WDC WD30EFRX Red drives. Can someone tell me which technology is used for this particular model number? I am trying to trace down a performance problem and if its SMR, that would explain a lot.

Probably because this series it is technology of 2013 … for NAS storage.

SMR has issues only at PC RAID configuration, slow performance at Array rebuild, etc etc…
When in use as single HDD, there is no performance penalty.

For any new PC Raid Array we buy Gold Series…

Thank you for the link. I stumbled on that one before I posted this. It is missing all WD30 for some weird reason, it goes from 20 to 40 missing 30. But I did find this: On WD Red NAS Drives - Western Digital Corporate Blog see April 22, 2020. This leads me to think its a SMR.

More background, I was testing out ZFS on these disks which are indeed very old because they were recently replaced by some HD disks. My plan was to do a backup to these disks and then turn the server off and move it offsite, since they are just sitting around doing nothing they might as well be my offsite backup. I also have onsite backups so if the old disks fail, they fail.

Any model before year 2018 SATA, SAS CMR (PMR) WDC
Any model before year 2019 SATA, SAS CMR (PMR) HGST

Also, WD’s blog identifies the WD30EFRX as CMR: