Yes, you have found a replacement drive. Older drives used to have a smaller cache and slower data transfer speeds.
Sustained Speed HDD 180 MB/s [ST4000VN008]
vs
Sustained Speed HDD 256 MB/s [ST4000VN006]
Cache size is not important in a RAID setup. But speed will make a difference.
I hope this helps.
https://nascompares.com/answer/hdd-price-per-tb/
P.S. Yes, ds923+ is coming soon.
Sustained Speed HDD 180 MB/s [ST4000VN008]
vs
Sustained Speed HDD 256 MB/s [ST4000VN006]
Cache size is not important in a RAID setup. But speed will make a difference.
I hope this helps.
https://nascompares.com/answer/hdd-price-per-tb/
P.S. Yes, ds923+ is coming soon.