Along with Samsung's release of the 840 Pro SSD today, Samsung is also releasing a more mainstream oriented 840 SSD. It's based around the same Samsung MDX controller as the Pro series, but uses 3-bit-per-cell (TLC) NAND instead of 2-bit-per-cell (MLC) NAND found in the 840 Pro. The 840 Pro also has a firmware which is tuned for heavier workloads consisting of more writes and random IOs, whereas the 840 is designed more towards read centric (i.e. consumer) workloads.

Samsung SSD 840 Pro vs 840 vs 830
  Samsung SSD 830 (256,512GB) Samsung SSD 840 (500GB) Samsung SSD 840 Pro (256,512GB)
Controller Samsung MCX Samsung MDX Samsung MDX
NAND 27nm Toggle-Mode 1.1 MLC 21nm Toggle-Mode 2.0 TLC 21nm Toggle-Mode MLC
Sequential Read 520MB/s 540MB/s 540MB/s
Sequential Write 400MB/s 330MB/s 450MB/s
Random Read 80K IOPS 98K IOPS 100K IOPS
Random Write 36K IOPS 70K IOPS 78K IOPS

Samsung is actually the first manufacturer to publicly release a TLC NAND based SSD, so we will have very interesting time testing it. Remember, adding more bits per cell reduces endurance and also increases program, erase and read latencies. In a Q&A session Samsung couldn't tell us any exact P/E cycle numbers, but they claimed that the 840 has higher endurance than many competitors MLC based SSDs. We didn't get more specifics than that, but we hope to be able to test this as soon as possible. As for the performance, Samsung again wouldn't tell us any raw latency numbers, but they said their TLC NAND is roughly 50% slower than their MLC NAND. For a more in-depth look at the architectural differences between MLC and TLC, refer to our Understanding TLC NAND article.

Samsung SSD 840 Series Pricing
  64GB 128GB 256GB 512GB
Samsung SSD 840 N/A $109.99 (120GB) $199.99 (250GB) $449.99 (500GB)
Samsung SSD 840 Pro $99.99 $149.99 $269.99 $599.99

The regular 840 SSD will be available in capacities of 120GB, 250GB and 500GB. The increased amount of spare area makes sense given the use of lower endurance TLC NAND. The 840 will be available as a bare drive or in a notebook kit, which adds $20 to the prices in the table. Both, the 840 and 840 Pro will be available on October 15th.

Samsung only provided 256GB 840 Pro SSDs for reviews, so unfortunately we haven't been able to test the 840 yet. However, I should get our review sample later today and hopefully some other capacities of the 840 Pro as well. 



View All Comments

  • Death666Angel - Monday, September 24, 2012 - link

    Sounds like Reply
  • surt - Wednesday, September 26, 2012 - link

    2^N is never divisible by 3. This is due to the principle of unique prime factorization. Reply
  • sweetie peach - Tuesday, September 25, 2012 - link


    screw irony
  • ajp_anton - Tuesday, September 25, 2012 - link

    2^0 = 1, not divisible by 3.
    2^n = 0 doesn't exist, unless n -> -∞, in which case I'll gladly give you -∞ $.
  • Old_Fogie_Late_Bloomer - Monday, October 1, 2012 - link

    /thread Reply
  • k2_8191 - Monday, September 24, 2012 - link

    The first chart of this article says 840 is MLC(2bits/cell) and 840 Pro is TLC.
    But it contradicts the performance nature.
    Perhaps their values are swapped?
  • Kristian Vättö - Monday, September 24, 2012 - link

    You're right, sorry about that, it's fixed now! The schedule in Korea has been pretty strict, so I didn't have too much time to write this article :-) Reply
  • k2_8191 - Thursday, September 27, 2012 - link

    Thanks for the fix! =) Reply
  • iwod - Monday, September 24, 2012 - link

    I hope the retail price will be a little lower. Given it is using TLC, its price is actually the same as current MLC 120GB SSD. Assuming 840 Pro will be faster then 840, then there are lots of other options that provide equal or slightly less performance with MLC for the same price. Reply
  • Chas1 - Monday, September 24, 2012 - link

    Wouldn't that equate to 256 Terabytes? Reply

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