Samsung SSD 850 Pro (128GB, 256GB & 1TB) Review: Enter the 3D Era
by Kristian Vättö on July 1, 2014 10:00 AM ESTRandom Read/Write Speed
The four corners of SSD performance are as follows: random read, random write, sequential read and sequential write speed. Random accesses are generally small in size, while sequential accesses tend to be larger and thus we have the four Iometer tests we use in all of our reviews.
Our first test writes 4KB in a completely random pattern over an 8GB space of the drive to simulate the sort of random access that you'd see on an OS drive (even this is more stressful than a normal desktop user would see). We perform three concurrent IOs and run the test for 3 minutes. The results reported are in average MB/s over the entire time.
Random performance is also brilliant and the 850 Pro tops almost all of our benchmarks. It is no wonder why it is so fast in the Storage Benches.
Sequential Read/Write Speed
To measure sequential performance we run a 1 minute long 128KB sequential test over the entire span of the drive at a queue depth of 1. The results reported are in average MB/s over the entire test length.
The same goes for sequential speeds. Of course, the differences are not substantial but nevertheless the 850 Pro is fast.
AS-SSD Incompressible Sequential Read/Write Performance
The AS-SSD sequential benchmark uses incompressible data for all of its transfers. The result is a pretty big reduction in sequential write speed on SandForce based controllers, but it doesn't impact most of the other controller much if at all.
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Krakadoom - Saturday, September 27, 2014 - link
I bought the 850 Pro 500 GB version. The transfer speeds are around (and just under) 400 MB/s and the IOPS are always around 55-60k. Not impressed - considering returning it just due to the huge gap between the rated specs and actual performance. (Of course Samsung Magician over-reports the transfer speed by quite a large margin).stealth_lee - Wednesday, October 1, 2014 - link
Someone just tipped me that V-NAND in Samsung 850 Pro is actually TLC not MLC.The first reason is the 86Gbit/die number is odd, if 850 Pro uses a TLC 128Gbit/die and emulates it to MLC then it would be 86Gbit/die, the numbers fit well.
The second reason is Chipworks confirmed it in the die shots:
http://bit.ly/YTVm9Z
http://bit.ly/1uByKcm
I'm just the messenger here, I'm not expert.
So...I was wodering is it possible to hack Samsung 850 Pro to get extra storage space in TLC?
wcatlan - Saturday, October 25, 2014 - link
Why isn't the lack of power loss protection a showstopper for any of these drives? I love the speed and reliability benefits under normal operation, but how can anyone get excited about a drive that can get corrupted in an instant due to power loss or computer freeze, where a hard shutdown is required? Seems that these drives are more prone to massive data issues much more than HDDs under the same power fault conditions. I keep looking for a good answer, but it seems smart people are willing to look past this seemingly fatal Achilles heal. Not sure what I might be missing. Any thoughts?futurefilm - Monday, December 1, 2014 - link
Today, Cyber Monday deals on Amazon, the 850 Pro 256 is going for $150. The 128 for $100. Get it now while it's hot.saagar - Thursday, January 22, 2015 - link
Dear Kristian Vättö,Fantastic review of the drives and the technology behind it. This is what readers like me expect to see on Anandtech. Thanks for breaking it down. Keep up the good work!
gsuburban - Wednesday, April 8, 2015 - link
As of April 8, 2015, the 850 Pro 256GB SSD can be had for about $144 if you look hard enough.rockfella79 - Saturday, June 27, 2015 - link
I love my 850 Pro 128 GB SSD :)KDT - Thursday, March 24, 2016 - link
Please update the endurance to 300TBW for 1TB model. This was my basis for buying this SSD. This is 2nd to Crucial MX200 (320TBW on 1TB model) in terms of endurance - for client/consumer SSDs.BimmerInd - Sunday, June 26, 2016 - link
Samsung is using 40nm over Micron's 16nm. Doing the math implies that for every 2.5 16nm Micron nodes in planar section, Samsung only does 1 40nm node. If we scale vertically to 32 layers, then Micron (or others for that matter) still do only 2.5 nodes for every 32 nodes of Samsung. Which means for every 16nm node, Samsung provides 12.8 nodes. Meaning the density scaling factor for every 32 layer increments is a multiple of 12.8. Assuming the current die size for 32 layers to be 128Gbit, then the density advantage for 256Gbit is 12.8x2 times, 512Gbit is 12.8x4 times and for 1Tbit in 2017 should be 12.8x8 times for 256 layers of nodes stacked on top of each other. So the density advantage is approximately 102.4% (theoretically). Samsung can theoretically produce a 1Tbit die at a cost advantage/space advantage of nearly 100 times compared to planar and manufacturers. It is almost like you are able to earn 100 times the profit for the same die provided the cost per bit is scaled along without passing on the price advantage to the end users until other players enter 3D market.The same is the case with Intel's 3D Cross Point Technology. They are having a new tech in their hands that is faster than NAND and closer to DRAM. So they are also planning to price it exactly between NAND and DRAM. We are already paying high costs to shift from platters to NAND and are going to pay even more to make a shift from NAND to 3D xPoint. I just wish I can jump a few years to the future, grab a high capacity NAND/xPoint drive for cheap and come back to the present and use it. Sigh !
BimmerInd - Sunday, June 26, 2016 - link
By the way this is just a rough calculation and is not to be taken literally.