RAID on Synology

[Enquiries]

I have a Synology DS1621xs+ and want to understand the performance differences on DSM 7 for RAID/cha choices/

Have a 10G network, 24GB RAM, and two empty M.2 slots for cache.

I don't need much space (8TB) but I do want a larger array to improve performance. The lowest cost would be a RAID 1 with two 8TB but that is the slowest option?

RAID five is fastest solution? but how much performance gain do you get as you add drives?

Also limited to drives that Synology allows with specific firmware is hard to find a newer drive that matches. the best cost drive I can find is an Exos X16 16TB Seagate Recertified $150 with a 2-year warranty. But wanting a fast array , the smallest I would have three disks or 32TB which is 4 times the space I need. 5 2TB drives are more $ than the 3 16TB.

Isn't it bad on RAM and Cache requirements to have tons of free space? Or can you just not assign part of the space?

I usually overthink everything. Please help with a solution for this platform.

[ed]

RAID 5 on your Synology DS1621xs+ will indeed provide a good balance of performance, capacity, and data protection. With your 10G network and 24GB of RAM, RAID 5 with three or more drives can enhance read performance significantly, as data is striped across multiple disks. As you add more drives, the performance generally improves, especially in read operations. However, RAID 5 does come with a write penalty due to the parity calculations. Given your need for 8TB of storage, RAID 1 with two 8TB drives is the simplest and most cost-effective solution but offers limited performance and no speed benefits from additional drives. Considering the performance boost you desire, RAID 10 might be a viable alternative as it combines RAID 1 and RAID 0, providing both redundancy and increased performance, though it requires more drives and results in less usable space.

Regarding the drive compatibility issue, using non-Synology approved drives like the Seagate Exos X16 16TB is possible, though you might encounter warning messages which can be disabled. For a cost-effective and high-performance setup, you could opt for three Exos X16 16TB drives in RAID 5, giving you a robust and fast array with ample space. Alternatively, five 2TB drives in RAID 5 would also work, but it might be more expensive and less efficient.

NVMe SSDs for caching are another excellent way to boost performance, especially for read-heavy tasks. If you opt for NVMe SSDs, ensure they have high endurance ratings, such as the Synology SNV3400 or Seagate FireCuda 510, with DWPD ratings of 0.66 and 0.7 respectively. Check out the list of reliable NVMe options here: https://nascompares.com/answer/nvme-m-2-...dwpd-mtbf/