Micron M500DC (480GB & 800GB) Review

Final Words

Overall the M500DC is a sensible addition to Micron's enterprise SSD lineup. It fills the gap between the consumer M500 and the P400m by providing a solution that is affordable yet has the feature set and meets the performance requirements of enterprise customers. The performance is actually far better than I expected from an entry-level drive, although I must admit that I was surprised (and perhaps a little terrified too) when I noticed that Micron sets aside up to 42% (!) of the NAND for over-provisioning and RAIN. While this isn't anything new for Micron (45% of the NAND in the P400m is inaccessible to the user), it's certainly a lot given that most of the competitors are only setting aside 27% or 12% of the NAND.

I think this is also where Micron's strength culminates. While using every possible bit in the NAND is crucial for the fab-less competitors to cut costs, Micron can use a bit more NAND for over-provisioning while remaining competitive in price as the NAND is so much cheaper for them. That also helps with the R&D costs because unlike Intel and many others, Micron isn't designing their own controller but relies on Marvell for the silicon.

Pricing in the enterprise space behaves a bit differently than in the client world. As drives are generally purchased in bulk, Micron couldn't provide any specific MSRPs for the drives, hence I had to rely on one of their resellers. The above table uses Arrow's pricing to give some idea of the typical cost. The Intel S3500 prices are Intel's bulk prices listed on their site but I'd like to emphasize that the prices here may not be very accurate and potential buyers should consult their distributors before making any purchasing decisions.

Update: Micron just sent us a note that one of their other resellers, CDW, sells the M500DC at noticeably lower prices, so I've updated the pricing table with the new prices. CDW also carries the S3500 and I've included its retail price in the table as well. Still, customers buying straight from Micron should expect even lower pricing as these single unit prices.

The M500DC carries a small premium over the S3500, but then it often performs substantially better as well. Most of the difference is due to the amount of NAND Micron sets aside for over-provisioning and NAND because that NAND is still a part of the bill of materials. If we compare the price against the total amount of NAND onboard, the pricing of the M500DC doesn't look that bad ($0.79/GiB vs $1.06/GiB for the S3500 at 480GB). I'm still not convinced that setting aside that much NAND is the best solution but it's understandable when seeking maximum performance and reliability for enterprise workloads. As the NAND lithographies get smaller, the increasing over-provisioning is the trade off that has to be made in order to avoid impacts on performance and endurance.

Ultimately, there is no one drive that is the best in all aspects and it's up to one's workload to find out the most suitable drive. I believe the M500DC provides a well balanced solution for the hyperscale customers that require consistent performance but are not looking for extreme endurance. The hyperscale market is quickly growing and will continue to do so and more affordable enterprise SSDs with regular MLC will continue to aid that growth.