Samsung 845DC PRO - good choice? (sustained 50k TPS at < 0.80$/gb)

A few months passed and we finally got everything ready to benchmark these drives. We’ll post the results within the next weeks but from our first findings we can tell that: they certify for 3x easily but exceed latency SLAs (6-7% >1ms) at 6x without OP. At 1x you’ll find 97% completing below 0.128ms… At any load, there are hardly any requests > 8ms.

What we also found is that additional overprovisining of 21% still helps a lot with the latency and they pass at 6x and complete at 12x (stress test running atm) with slightly higher latencies. Atleast one of our drives manages to run at 12x for atleast 24 hrs without OP at reasonable latency increase. We are still testing to find a stable setting, since we’ve experienced some issues with ACT when we tested with Ubuntu. CentOS seems to be more stable.

The 845DC-drives have a periodic latency increase (some algo running every 5 to every 65 seconds) that is responsible for atleast 50% of the average latency. Not sure how common that is. However, we are still very happy with the drives especially due to their economics. They are rated at 10 DWPD and can be had for $0.68 per GB capacity (B2B-price). We’ll most likely go for a large namespace with these drives and a smaller one backed by NVMe’s for the ultra-hot dataset (if required at all).

EDIT: You can find our benchmark results here.