The original post: /r/datahoarder by /u/greenie4242 on 2024-08-19 09:20:39.
I purchased five Recertified Seagate EXOS X18 16TB ST16000NM000J SATA drives for use in a Synology DS423+ NAS. One as a cold spare. Running SHR-2, need redundancy not capacity.
Hard Disk Sentinel Pro on a spare PC testing all drives multiple times before installing them in the NAS revealed one drive significantly slower than the other four. About 10-12% slower which doesn't sound like much but adds 4+ hours to a full-surface sequential read/write test. Strangely another drive that consistently matches the other 'fastest' drives in short speed tests runs about 4% slower during extended operations. All HDDs reformatted to 4K Native before running tests. Swapping to different SATA ports made no difference.
R/W surface scan: 45 hours 53 minutes slowest 43 hours 21 minutes slower 41 hours 53 minutes fastest
The fast drives all almost exactly match the sustained maximum and minimum specifications from the official Seagate data sheet, but the slow drive is about 10-12% slower than spec. Otherwise they all seem to perform well. Seek times are identical.
From datasheet: Max. Sustained Transfer Rate OD (MB/s, MiB/s) 270/258 Random Read/Write 4K QD16 WCD (IOPS) 170/550
R/W Transfer speed curves look fine with the fast drives starting at 263MB/s and slow drive starting at 230MB/s then all gradually slowing down but never below 110MB/s. Temperature curves all look fine with some drives reaching 40C and a couple reaching 48C which could be due to the enclosure.
Even the slowest drive will of course easily saturate the gigabit LAN port, but I'm concerned something might be wrong with the drive. Also it'll take an extra 4+ hours to rebuild the array when needed. Maybe Seagate artificially speed limited it during the recertification process? I don't know.
Should I contact the seller for a replacement, or is this a non-issue? The warranty is through an Australian reseller, not a standard Seagate RMA. Hopefully they'll be fine with it, but I'd rather not have to go through the process if it can be avoided. I can keep the slower drive as the cold spare, but if it's already faulty in some way that might be a future problem I can nip in the bud right now.
I'd appreciate any advice from people with experience running multiple EXOS drives who may have encountered a similar situation. Thanks in advance!