The Samsung SSD 850 120GB Review: A Little TLC for SATA
by Billy Tallis on November 27, 2017 12:00 PM ESTAnandTech Storage Bench - Light
Our Light storage test has relatively more sequential accesses and lower queue depths than the Heavy test, and it's by far the shortest test overall. It's based largely on applications that aren't highly dependent on storage performance, so this is a test more of application launch times and file load times. This test can be seen as the sum of all the little delays in daily usage, but with the idle times trimmed to 25ms it takes less than half an hour to run. Details of the Light test can be found here. As with the ATSB Heavy test, this test is run with the drive both freshly erased and empty, and after filling the drive with sequential writes.
The Samsung SSD 850 120GB manages to deliver an average data rate that is slightly higher than even the 128GB 850 PRO on the Light test, when the drives are empty. On a full drive, the 850 PRO retakes the lead.
The average and 99th percentile latencies of the Samsung 850 120GB are not the best, but like the other Samsung drives it doesn't experience a catastrophic breakdown of performance when full. The drives using Micron 3D TLC all lose control over latency.
The 850 120GB shows a substantial difference in average read latency between test runs with a full or empty drive. The average write latency is completely unaffected, while the Micron 3D TLC drives end up stalling write commands when their write buffers overflow.
The 99th percentile latency figures further emphasize the difference in behavior between the Samsung drives and the SMI+Micron drives. All of them perform fine in ideal conditions, but the Samsungs are much better at handling the pressure of operating while full. The 850 PRO 128GB and the 850 EVO 250GB show a much smaller impact to read latency than the 850 120GB and the other two Samsung 120GB TLC drives.
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lilmoe - Monday, November 27, 2017 - link
Oh, and so are the Pros... hmmm.Is that a holiday discount or is it that I haven't checked the price in a while?
Arbie - Tuesday, November 28, 2017 - link
Great article, even though its subject is a minor league item. AT quality.bug77 - Tuesday, November 28, 2017 - link
That's the ugly face of SSD: the cheaper they make them, the more we lose durability and access speed...bcronce - Tuesday, November 28, 2017 - link
Still 1000x faster than a mechanical drive, perceptibly as fast as any other SSD for most situations, and will last a lifetime.mapesdhs - Wednesday, November 29, 2017 - link
Definitely will not last a lifetime, and some newer models can have worse steady state performance than a rust spinner.bcronce - Wednesday, November 29, 2017 - link
Even the infamous Samsung 840s were still out-performing 15k SAS drives in their degraded modes. I see free "crackerjack" USB 2.0 flash drives out performing my 7.2k RPM rust buckets.MamiyaOtaru - Thursday, November 30, 2017 - link
no you don'tyifu - Saturday, December 2, 2017 - link
power efficiency test pleaseyifu - Sunday, December 3, 2017 - link
Billy , I would really want to see , is not only the speed , but the power efficiency for a older laptop like my MacBook Pro 13in 2012. if some one really care about speed , they will go for 850 pro 850 EVO, or PCIE. my gaming PC is with 960 pro for windows and 850 evo for storage. my iMac for work is with apple PCIE and a Toshiba HK4R 960GB (power lost protection). SATA speed for a ssd is done.the speed difference between those cheap SSDs are to small.I am thinking to "upgrade" my MacBook Pro mid 2012 from 840 pro to a slower but very very power efficient SSD.
finefunny - Sunday, December 3, 2017 - link
The company has already released several new versions of its OEM models, such as the PM871b, with 64-layer V-NAND. These drives often sell in basic systems from Dell, Lenovo, and other OEM brands. Customers often do not select the components in those systems, so the OEM models fly under the radar.Samsung isn't saying much for now, but it should answer our questions in early 2018. That's when we expect it to roll out new retail SSDs.