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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YazX_ - Monday, July 7, 2014 - link
Prices are not going down, good thing we have Crucial who have best bang for the buck, ofcourse performance wise is not compared to sandisk or samsung, but its still a very fast SSD, for normal users and gamers, Mx100 is the best drive you can get for its price.soldier4343 - Thursday, July 17, 2014 - link
My next upgrade the Pro 850 512gb version over my OCZ 4 256gb.bj_murphy - Friday, July 18, 2014 - link
Thanks Kristian for such an amazing, in depth review. I especially loved the detailed explanation of current 2D NAND vs 3D NAND, how it all works, and why it's all so important. Possibly one of my favourite Anandtech articles to date!DPOverLord - Wednesday, July 23, 2014 - link
Looking at this it does not seem to be a HUGE difference than raid 0 of 2 Samsung Pro 840 512GB (1tb in raid 0).To upgrade at this point does not make the most sense.
Nickolai - Wednesday, July 23, 2014 - link
How are you implementing over-provisioning?joochung - Tuesday, July 29, 2014 - link
I don't see this mentioned anywhere, but were the tests performed with RAPID enabled or disabled? I understand that some of the tests could not run with RAPID enabled, but for those other tests which do run on a formatted partition (i.e. not run on the raw disk), its not clear if RAPID is enabled or disabled. Therefore its not clear how RAPID will affect the results in each test.Rekonn - Wednesday, July 30, 2014 - link
Anyone know if you can use the 850 Pro ssds on a Dell PERC H700 raid controller? Per documentation, controller only supports 3 Gb/s SATA.janos666 - Thursday, August 14, 2014 - link
I always wondered if there is any practical and notable difference between dynamic and static over-provisioning.I mean... since TRIM should blank out the empty LBAs anyway, I don't see the point in leaving unpartitioned space for static over-provisioning for home users. From a general user standpoint, having as much usable space available as possible (even if we try to restrict ourself from ever utilizing it all) seems to be a lot more practical (until it's actually usable with an acceptable speed, so even if notably slower but still fast enough...) than keeping a (significantly more, but still not perfectly) constant random write performance.
So, I always create a system partition as big as possibly (I do the partitioning manually: a minimal size EFI boot partition + everything else at one piece) without leaving unpartitioned space for over-provisioning and I try to leave as much space empty as possible.
However, one time, after I filled my 840 Pro up to ~95% and I kept it like that for 1-2 days, it never "recovered" . Even after I manually ran "defrag c: /O" to make sure the freed up space is TRIMed, sequential write speeds were really slow and random write speeds were awful. I ha to create a backup image with DD, fill the drive with zeros a few times and finally run an ATA Secure Erase before restoring the backup image.
Even though I was never gentle with the drive (I don't do stupid things like disabling swapping and caching just to reduce it's wear, I bought it to use it...) and I did something which is not recommended (filled almost all the user-accessible space with data and kept using it like that for a few days as a system disk), this wasn't something I expected from this SSD. (Even though this is what I usually get from Samsung. It always looks really nice but later on something turns out which reduces it's value/price from good or best to average or worse.) This was supposed to be a "Pro" version.
stevesy - Friday, September 12, 2014 - link
I don't normally go out of my way to comment on a product but I felt this product deserved the effort. I've been using personal computer since personal computers first came out. I fully expected my upgrade from an old 50gig SSD to be a nightmare.I installed the new 500gig Evo 850 as a secondary, cloned, switch it to primary and had it booting in about 15 minutes. No problems, no issues, super fast, WOW. Glad Samsung got it figured out. I'll be a lot less concerned my next upgrade and won't be waiting until I'm at my last few megabytes before upgrading again.
basil.bourque - Friday, September 26, 2014 - link
I must disagree with the conclusion, "there is not a single thing missing in the 850 Pro". Power-loss protection is a *huge* omission, especially for a "Pro" product.