Conclusion, Pricing, and Final Thoughts
- 2TB is the highest available capacity in 2.5"x7mm SATA form factor
- Excellent sequential read / write / random IOPS performance
- Industry leading warranty and endurance rating
- Competitive introductory MSRP
- 2TB 850 EVO showed a low QD weakness in sustained mixed workloads
- Total cost of so much flash capacity may cause sticker shock (see below)
* (850 Pro = 2048 GB)
- 850 Pro: 10 years
- 850 EVO: 5 years
To reiterate the specs, the 2TB 850 Pro is rated at 300 TBW, while the 850 EVO is rated at 150 TBW. These ratings were simply carried forward from the 500GB/512GB models, meaning that the 2TB models should be theoretically capable of 4x those figures (1.2 PBW / 600 TBW). Divide that over whichever usage time you prefer, but remember the warranty is rated at a more 'reasonable' consumer workload of 80 GB/day regardless.
Samsung was first to market with 3D VNAND flash memory, and now they are first to stack this flash to new heights with two SSD models coming in at a full 2 Terabytes of capacity. Samsung has decided that the time is right for such an entry into the market, and minus a small performance hiccup with the 2TB 850 EVO, they have executed the necessary performance upgrades to keep their SSD controllers moving data at expected speeds while handling a massive amount of flash. To put this into perspective, consider that the 2TB 850 EVO has 128 flash memory dies, while the 2TB 850 Pro has 192! The pricing is very competitive, especially for a launch MSRP of a product with no competition at that capacity. The only question is if potential customers can handle the total cost of 2TB worth of flash – even at such a low cost/GB.
Award for the 2TB 850 Pro:
The 2TB 850 Pro gets Gold, the only detractor being sheer cost. $1k is a lot for a consumer SSD any way you slice it.
Award for the 2TB 850 EVO:
The 2TB 850 EVO gets Silver due to the odd performance seen during mixed workloads. We suspect this sort of issue can be 'tuned out' in firmware and will keep an eye out for future optimizations. Should Samsung correct that issue in the future, I will revise this space accordingly.