Samsung 850 EVO
SATA 2.5" · SATA 6 Gbps · Samsung MEX
Specifications
| Interface | SATA 6 Gbps |
|---|---|
| Controller | Samsung MEX |
| NAND Type | Samsung 32-layer 3D V-NAND TLC |
| DRAM Cache | LPDDR3 |
| Warranty | 5 years |
| Active Power | 2.1 W |
| Idle Power | 0.05 W |
| Seq Read | 540 MB/s |
|---|---|
| Seq Write | 300 MB/s |
| Rand Read | 97,000 IOPS |
| Rand Write | 88,000 IOPS |
| Endurance | 75 TBW |
| Part Number | MZ-75E120B |
| DRAM Cache | 512MB LPDDR3 |
| Seq Read | 540 MB/s |
|---|---|
| Seq Write | 520 MB/s |
| Rand Read | 98,000 IOPS |
| Rand Write | 90,000 IOPS |
| Endurance | 75 TBW |
| Part Number | MZ-75E250B |
| DRAM Cache | 512MB LPDDR3 |
| Seq Read | 540 MB/s |
|---|---|
| Seq Write | 520 MB/s |
| Rand Read | 98,000 IOPS |
| Rand Write | 90,000 IOPS |
| Endurance | 150 TBW |
| Part Number | MZ-75E500B |
| DRAM Cache | 1GB LPDDR3 |
| Seq Read | 540 MB/s |
|---|---|
| Seq Write | 520 MB/s |
| Rand Read | 98,000 IOPS |
| Rand Write | 90,000 IOPS |
| Endurance | 150 TBW |
| Part Number | MZ-75E1T0B |
| DRAM Cache | 1GB LPDDR3 |
| Seq Read | 540 MB/s |
|---|---|
| Seq Write | 520 MB/s |
| Rand Read | 98,000 IOPS |
| Rand Write | 90,000 IOPS |
| Endurance | 300 TBW |
| Part Number | MZ-75E2T0B |
| DRAM Cache | 2GB LPDDR3 |
Overview
Samsung's 850 EVO replaced the 840 EVO in mid-2014 and stayed in Samsung's lineup until the 860 EVO arrived in 2018. It was not the first consumer drive with 3D NAND (the 850 PRO beat it by a few months), but it was first to bring Samsung's V-NAND to the mainstream at a lower price than the 850 PRO. Eventually, it came to three form factors: 2.5", mSATA and M.2 SATA.
Compared to planar TLC drives on the market at launch, the 32-layer V-NAND gave the 850 EVO better write endurance despite using the same 3-bits-per-cell cell type. The 120GB model is an outlier: sequential write speed drops to 300 MB/s because fewer NAND dies means less write parallelism. The 250GB and larger models all reach 520 MB/s sustained write, meaning that it largely saturates the interface's bandwidth.
Samsung's TurboWrite feature uses a portion of the NAND as a dynamic SLC write buffer. Within that buffer, transfers run at SLC speeds; past it, the drive writes directly to TLC cells at reduced throughput. The buffer size scales with capacity, ranging from around 3GB on the 120GB model to 12GB on the 2TB.
The 2TB capacity, available from 2016, was unusually large for a mainstream consumer 2.5" drive at the time. The 850 EVO was one of a small number of drives to reach that capacity point before the 860-series took over the product slot.
Variants
The 850 EVO also shipped in mSATA and M.2 SATA (2280) form factors with identical performance specifications. Capacities differed somewhat depending on the form factor, with the M.2 version topping out at 1TB.
Reviews
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“Not only is the endurance higher, but the 850 EVO's performance is also better compared to its predecessor. In our 2011 Storage Benches the 850 EVO matches up with the 850 Pro and is hence one of the fastest SATA 6Gbps SSDs for typical client workloads. In very heavy workloads, illustrated by our 2013 Storage Bench, the 850 EVO does okay, but it's clear that it's outperformed by drives that are more optimized for such usage.”
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“Looking at performance, the 2TB Samsung 850 EVO posted both best-in-class, bar-setting numbers and results that were less than that of its smaller capacities brothers.”