This gen2 Flashtor FS6812X shows good write performance. I previously used an FS6712X, and no matter what I tried whether RAID 5 or RAID 10 (12×4TB) I couldn't achieve a sustained write speed beyond 700 MB/s. I initially suspected the limitation was due to using DRAM-less SSDs, but that turns out not to be the root cause.

Today I received the new FS6812X Gen2, and simply migrating the exact same set of SSDs into it gave a significant boost: write speed is now almost a constant 1.18 GB/s in a 500GB single file transfer test (raid 10).

The FS6712X only has 8 PCIe lanes, which creates a bottleneck when all 12 SSDs compete for bandwidth. This resulted in frequent write stalls, disk activity would drop to zero for about 0.3 seconds every ~4 seconds as i observed in the per-disk activity graphs. The FS6812X doesn't suffer from this issue the disk write graphs are smooth and stable without sudden drops.

In terms of performance, the FS6812X is capable of saturating a 10GbE connection, while the FS6712X struggled with poor write speeds. I can't comment on long-term stability yet with this new unit, but i am happy with the write speed.

Ugly looking device. Looks like a PS4. Somehow makes qnaps look good in comparison.