Random 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.

Desktop Iometer - 4KB Random Read

Desktop Iometer - 4KB Random Write

Desktop Iometer - 4KB Random Write (QD=32)

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.

Desktop Iometer - 128KB Sequential Read

The same goes for sequential speeds. Of course, the differences are not substantial but nevertheless the 850 Pro is fast.

Desktop Iometer - 128KB Sequential Write

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.

Incompressible Sequential Read Performance

Incompressible Sequential Write Performance

AnandTech Storage Bench 2011 Performance vs. Transfer Size
Comments Locked

160 Comments

View All Comments

  • Homeles - Monday, June 30, 2014 - link

    Man, the 850 Pro is killer. Samsung really knocked it out of the park. Those prices are just completely out of touch, though.
  • Awful - Monday, June 30, 2014 - link

    Yeah the prices are high for now. Game changing stuff though; and prices can only come down. PCIe V-NAND? Yes please!
  • Hung_Low - Tuesday, July 1, 2014 - link

    Even better, Intel style NVMe controller + this v-nand!! orgasmic
  • avyshue - Tuesday, July 1, 2014 - link

    yeah, i've been holding off on upgrading from my existing 128 boot drive + mechanical setup to a full 1TB drive. I think I'll keep holding out until PCIe is better supported/better priced.
  • Angrychair - Tuesday, July 1, 2014 - link

    The prices are in line for class leading performance and reliability.

    The reliability is the critical part, these are drives that are unlikely to wear out in any system almost no matter how heavily taxed.
  • Ken_g6 - Tuesday, July 1, 2014 - link

    I see these are MLC drives. Hopefully, Samsung will come out with consumer-level 3D TLC drives that have relatively good reliability, and a price at or below Crucial's drives.
  • frenchy_2001 - Tuesday, July 1, 2014 - link

    Reliability is a side effect of retreating to 40nm pitch technology.
    Even if they decided to do TLC with the same cells, they would probably end up being more reliable than 2D nand MLC.
  • joelypolly - Thursday, July 3, 2014 - link

    They already have drives in testing that has written over 8 petabytes so I think the reliability is there
  • mkozakewich - Saturday, July 5, 2014 - link

    On that note, I'm wondering how 4-bit MLC would perform compared to 2D NAND.
  • RaistlinZ - Monday, June 30, 2014 - link

    Fantastic drives! That consistency is really remarkable. I don't know if most will pay the price premium for these over the EVO however. The average user probably wouldn't notice a difference in general day to day use.

Log in

Don't have an account? Sign up now