Final Words

The Crucial BX200 comes in last place as often as not. The Crucial BX300 doesn't entirely reverse that, but it still provides one of the biggest generational jumps the SSD market has seen. Micron has learned from their mistakes with the BX200 and produced a worthy successor to the BX100. With the MX300 doing so well as a mainstream SSD with entry-level pricing, the focus of the BX line has shifted from simply being the cheaper option to being the drive designed specifically for the smaller capacities demanded by cost-conscious consumers.

Micron's large 384Gb 3D TLC die is ill-suited to making small SSDs, as 120-128GB SSDs end up only having 3 NAND chips on a four-channel controller, and even at larger capacities the flash is not well balanced across the controller channels. For the next generation of 3D NAND, Micron is addressing this issue by manufacturing both a large 512Gb die and a smaller 256Gb die. Since that 64-layer 3D NAND is still ramping up to full production, Micron has chosen for the BX300 to use their 256Gb 3D MLC that allows for a small SSD to be reasonably fast and free of the downsides of the TLC NAND that dominates the entry-level SSD market.

It's a bit of a puzzle how Micron can afford to sell an MLC SSD for less than their TLC SSD without making serious compromises elsewhere like using a DRAMless controller. But as long as they're willing to sell the BX300 at these prices, it's a great product.

The BX300 only has a few notable weaknesses. Micron's 32L 3D NAND is unusually power-hungry during sequential reads, despite being otherwise quite efficient. This also affects random reads to some extent. The BX300's peak performance is on average slightly below top-tier SATA drives like Samsung's 850 PRO and EVO and the Intel 545s, and it is outperformed by other 3D TLC drives like the MX300 and ADATA SU800 when they're able to make good use of their SLC caches. But this is offset by how well the BX300 retains its performance under heavier workloads and when operating with a nearly-full drive. In that respect, it has a significant advantage over the Crucial MX300.

  120-128GB 240-275GB 480-525GB 960-1050GB 2TB
Crucial BX300 $59.99 (50¢/GB) $89.99 (38¢/GB) $149.99 (31¢/GB)    
Crucial MX300   $99.99 (40¢/GB) $159.99 (32¢/GB) $289.99 (29¢/GB) $549.00 (27¢/GB)
ADATA SU800 $56.68 (44¢/GB) $91.99 (36¢/GB) $168.58 (33¢/GB) $265.00 (26¢/GB)  
ADATA SU900   $108.99 (43¢/GB) $197.80 (39¢/GB)    
ADATA XPG SX950   $109.99 (46¢/GB) $214.99 (45¢/GB)    
Intel SSD 545s   $99.99 (39¢/GB) $169.99 (33¢/GB)    
Samsung 850 PRO   $114.99 (45¢/GB) $212.19 (41¢/GB) $420.99 (41¢/GB) $897.99 (44¢/GB)
Samsung 850 EVO   $89.99 (36¢/GB) $174.75 (35¢/GB) $299.99 (30¢/GB) $715.00 (36¢/GB)

The Samsung 850 EVO is available with very competitive pricing at the moment, shutting many drives using Micron 32L 3D NAND out of the market. The MSRP of the 480GB BX300 we tested is low enough to beat basically everything on a price per GB basis, and is far enough below the Samsung 850 EVO that it isn't an automatic decision to get the Samsung instead. The 240GB BX300 will debut with the same price as the 250GB Samsung 850 EVO, making the Samsung the better option for now.

The smallest capacity of the Crucial BX300 may prove to be the most popular and most competitive. There are other 120GB drives on the market that are priced a bit lower, but the BX300 has the advantage that it uses 3D MLC NAND, doesn't use a DRAMless controller and uses all four NAND channels on its controller. The 120GB BX300 will be slower than the 480GB model we tested, but it will retain the general characteristic of performing almost as well when it is full as when empty. This is far more important at such small capacities. The 120GB BX300 also benefits from lack of competition from Samsung: the planar TLC-based 750 EVO is not available at competitive prices and the 120GB 850 EVO and 128GB 850 PRO were discontinued when Samsung moved from 32L 3D NAND to 48L 3D NAND.

Power Management


View All Comments

  • nathanddrews - Tuesday, August 29, 2017 - link

    SSD prices at Microcenter dropped by about 25% over the weekend (850 EVO 500GB for $139) and Amazon and Newegg are also down a bit, I assume the NAND shortage is over? Just clearing inventory? I'm really happy to see MLC back in the mix! Time to upgrade the last of the mechanical computers... Reply
  • ddriver - Tuesday, August 29, 2017 - link

    Oh no it is not. They are gonna milk that cow until Chinese NAND gets to the market. And then they will short the price.

    On a side note, way to go Crucial - making quality products with MLC flash, with endurance worse than that of TLC flash. It is quite the achievement.
  • ddriver - Tuesday, August 29, 2017 - link

    On the bright side, it is good to see that the competition is finally catching up to samsung SATA SSDs. Be that a couple of years after they stopped developing SATA SSDs. Reply
  • Yojimbo - Tuesday, August 29, 2017 - link

    I think Chinese production of NAND and DRAM will be by new companies operating in new foundries. Volume production probably won't be reached until 2019, and can we really be sure of what to expect when it does? Reply
  • leexgx - Saturday, September 02, 2017 - link

    you do know that endurance actually means warranty void if you use more than the endurance rating, MLC drives norm have endurance levels of PB of data before issues start to happen

    love the BX100 for its near 0 power use when idle but it does choke a little under high load meaning i actually notice it slightly when its struggling but still its many times faster then a HDD witch can get tied up under medium loads (like windows update and store)

    be nice if they can replicate that on the BX300 (should be better than the BX100 due to SLC cache and improved controller )
  • Ryan Smith - Tuesday, August 29, 2017 - link

    The NAND shortage is definitely not over. That won't abate until some time in 2018.

    I couldn't say if it was clearing inventory, a short-term deal, or something else, but right now there's no reason to believe any kind of price cuts will stick.
  • nathanddrews - Tuesday, August 29, 2017 - link

    So what you're saying is "get it while it's hot"? Reply
  • Ryan Smith - Wednesday, August 30, 2017 - link

    Yup. Reply
  • BrokenCrayons - Tuesday, August 29, 2017 - link

    I picked up a 480GB Muskin Reactor Armor3D for $139 _very_ recently dropped from $149. Like you, I was wondering if the NAND shortage was coming to an end, but Ryan is in a good position to know these things so maybe there's just a good deal on at the moment. Reply
  • Alexvrb - Tuesday, August 29, 2017 - link

    MLC or not the TLC Evo is still the better performing drive. If you're buying a ~250GB model the Evo is hands down the best option. At 500GB-1TB capacities there are a couple of cheaper options that are tempting but the Evo is still the best deal for the money IMHO until you hit 2TB class drives, where the MX300 really shines. Reply

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