luxjack

Thanks. I see we have the same zeroing speed, but the difference arises on the read phases - yours are much faster indeed. What I am surprised at is to see you got almost the same post-read speed as pre-read speed. In my experience, post-read is usually about half pre-read speed. But perhaps thats the different script - I use the standard version.

Hi, I regularly preclear 4TB drives - WD Reds/Greens - and this is my first HGST 4 TB 7200 RPM Deskstar. (Heretic posted a similar issue using the NAS version of this drive - sorry I cannot see how to quote it here). I too have had unusually slow pre-read times - essentially a 1-cycle preclear for this HGST drive takes as long as a WD 4TB 2-cycle preclear. I tried it on two different configs but similar results each time. I have no real worry about the drive - the post preclear smart looks fine but I add this here in case somebody is curious or interested to see why so slow. (Not a regular poster so apologies if I make errors - not sure how to reply and quote). invoked as: ./preclear_disk.sh -A /dev/sdb == HGSTHDS724040ALE640 PK2301PCHME5PB == Disk /dev/sdb has been successfully precleared == with a starting sector of 1 == Ran 1 cycle == == Using :Read block size = 8388608 Bytes == Last Cycle's Pre Read Time : 21:31:26 (51 MB/s) == Last Cycle's Zeroing time : 8:36:10 (129 MB/s) == Last Cycle's Post Read Time : 42:20:43 (26 MB/s) == Last Cycle's Total Time : 72:29:26 == == Total Elapsed Time 72:29:26 == == Disk Start Temperature: 34C == == Current Disk Temperature: -->43<--C, Preclear_Reports_HGST_4TB.txt