Samsung packs more speed, endurance into 850 Evo consumer SSDs

The 850 Evo will come in storage capacities of 128GB (US$99.99), 250GB ($149.99), 500GB ($269.99) and 1TB ($499.99). The drives, which will be available later this month, can be plugged into SATA storage slots in laptops and desktops.

The biggest advance in 850 Evo is the use of 3D V-NAND memory technology, which gives the drives more speed and durability than predecessors like the 840 Evo. The SSDs have storage units stacked on top of each other. That's a more power-efficient and speedy structure compared to the 840 Evo, in which storage units were placed next to each other.

The 850 Evo SSDs is two times more durable than the 840 Evo, said Richard Leonarz, senior marketing manager at Samsung.

The durability is based on the amount of data written to the SSD. Samsung estimates the 850 Evo durability to be 150TB of data written to the SSD, compared to 75TB for the 840 Evo models.

The speed improvements are best reflected in the random write speeds of the lower capacity 120GB and 250GB models. The lower-capacity SSDs have fewer data transfer channels, and a Samsung benchmark measures the random write speed at 88,000 IOPS (input/output per second), compared to 35,000 IOPS on the 840 Evo 120GB model, and 66,000 IOPS for the 250GB model.

Samsung has enhanced its buffer technology called TurboWrite to speed up writing of data blocks on the SSDs.

The 90,000 IOPS write speed on the higher-capacity 500GB and 1TB models are about the same as predecessors. The random read speeds of the 850 Evo SSDs are between 94,000 and 98,000, also in the same range as previous versions.

The 850 Evo sequential read speed is 540 megabytes per second and the write speed is 520 megabytes per second. That's also similar to the 840 Evo, according to Samsung's specifications.

Samsung has also addressed some read issues affecting 840 Evo users. The new technologies in 850 Evo bring better error correction to the drives, which should keep the reads and speeds stable, Leonarz said.

The V-NAND first appeared in Samsung's enterprise SSDs, but more consumer drives will now be based on the technology, Leonarz said.

Agam Shah covers PCs, tablets, servers, chips and semiconductors for IDG News Service. Follow Agam on Twitter at @agamsh. Agam's e-mail address is agam_shah@idg.com