Crucial is a big name in SSD’s and one we’ve only touched on tangentially to date. Although this will be our first look at a crucial direct product the bulk of the ssd’s we’ve looked at to date use one form or another of IMFT flash. This makes the BX300 particularly important as it is a demonstration of Micron’s own flash in a first party product. This should set a baseline for third parties. With that said today we have the BX300 one a budget oriented drive from crucial and a unique entry in the space considering it’s choice of memory.



IMFT is(or was) a joint venture between Micron and Intel to produce advanced memory devices. Although this partnership is potentially reaching it’s closure as the two companies flash interest diverge. Through it’s history IMFT has provided some of the major breakthroughs in the ssd industry. These include many of the early high performance drives and the most recent optane memory.

The BX300

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The packaging of the BX300 is in line with what we’re used to seeing with sata SSDs. The drive continues to include a 7mm to 9.5mm plastic spacer although I have never seen the utility of this to date. Opening up the drive brings a few suprises. We see a double sided PCB contraining a total of 8 packages, These appear to be single die packages(which would offer lower pagacing costs). The benifit of this is double sided in the form of lower packaging costs and increased active channels on the controller. The SM2258 in use here is a four channel controller and this configuration ensures operation in a two die per channel configuration. An aluminum shell and included thermal material should make for an interesting comparison to the last time we saw an SM2258 with MLC in operation in a plastic enclosure

Capacity 120GB 240GB 256GB
Controller SM2258 SM2258 SM2258
Firmware M2CR010
NAND Micron 1st Gen 256Gbit 3dMLC Micron 1st Gen 256Gbit 3dMLC Micron 1st Gen 256Gbit 3dMLC
Sequential Read 555 MB/s 555 MB/s 555 MB/s
Sequential Write 510 MB/s 510 MB/s 510 MB/s
4k Random Read 45,000 IOPS 84,000 IOPS 95,000 IOPS
4k Random Write 90,000 IOPS 90,000 IOPS 90,000 IOPS
Temperature range 0-70°C 0-70°C 0-70°C
Dimensions 7mm X 69.85mm X 100.5mm 7mm X 69.85mm X 100.5mm 7mm X 69.85mm X 100.5mm
Endurance 55TBW 80TBW 160TBW
Warranty 3 years 3 years 3 years

One of the key advantages to the low capacity packages used here is increased performance of lower capacity models. Outside of that we see Crucial is using a custom firmware on this drive, the impact of which  we’ll see during testing. Things are rounded out by healthy but not outstanding endurance ratings and warranties. the 240Gb sample we’re looking at is rated for 80TBW.


SSD-z doesn’t quite tell us as much as we’d like, fortunatley the missing data is in the spec table for this drive. What we do see is working TRIM for this drive. An interesting note is the firmware on the device appears to be micron specific using a different scheme than most Silicon Motion firmware we’ve seen. With that out of the way let’s see what the BX300 can do.

ATTO 3.05

Atto starts us off with a small surprise easily reaching the listed read and write speeds. We’re seeing consistent performance once the block sizes are at the 2MB size things flatten.

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Stacked up next to the other drives the BX300 brings in some, interesting results from ATTO. It took the drive larger sizes to reach it’s peak potential but when it did it’s coming in near or above even the reactor.

Crystal Disk Mark 5.1.2 x64

Crystal disk mark isn’t quite as surprising as ATTO was but is still in a good place. The BX300 is posting reads just below it’s specifications and writes at it sequentially. We’re used to seeing low capacity drives, especially budget ones struggle to quite reach those levels so this is a breath of fresh air in that arena.

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For a budget drive the BX300 is more than holding it’s own. It’s outperforming the 1TB reactor everywhere except 4k 32 tests where simply having 4 times as much nand to work with is to the benefit of the larger drive.


Anvil gives us a good look at response times. Driven by it’s newer controller the BX300 delivers some good times although it can’t come close to the KC1000 the SATA interface is the bottleneck here and only a new interface can solve that.

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That’s a lot of bars but they’re telling the same story we’ve seen for most of this review. The BX300 is faster than it deserves to be only being outshined where drives can leverage a faster interface(NVME) or a few places where the older Reactor is faster thanks to it’s capacity.


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AS SSD gives us a shock with the simulated test but we’ve seen that kind of result before.(Let me know in the comments if you find those useful they seem to be too inconsistent to be useful comparable data) In the rest of the tests however we see the BX300 outperforming everything that isn’t NVME, a position it’s been in this entire time.

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Stacked up AS SSD isn’t telling us anything new. The BX300 is faster than it should be considering it’s pricing.

Consistency Test

If this scatter plot looks familiar it’s because it’s the operation we’re used to seeing on silicon motion controllers. The initial filling of the drive(possibly aided by SLC cache) dropping to a bi stable operation after a period of time. It looks as if after an extended period the BX300 trends to pull results closer to it’s floor than it’s ceiling starting around 5000 seconds but this is impressive none the less.

This isn’t something I expected to see out of a budget drive. Although with how it’s performed in every other test I shouldn’t be too surprised. The BX300 sets a new high water mark for SATA based drives in this test besting it’s older siblings. It can’t quite compete with the KC1000 but that’s a premium NVME offering.


The BX300 is prices according to it’s target as a budget drive not it’s performance. Below 500GB there isn’t a lot of reason to suggest drives other than it unless they’re using NVME. Being in the same ballpark of drives like the SU800 shows Micron is serious about this budget effort.

Closing Thoughts

The BX300 represents an odd duck as a budget SSD. We’ve seen this controller and nand before set records for low performance not high. If it came in higher capacities the BX300 would be a contender for the mainstream/performance arena. Instead crucial is using it to crush options for lower cost drives making it a defacto recommendation below 1TB.  Crucial sells it’s MX series drives above that capacity. At 84.99 on amazon the 240GB BX300 we tested is a steal considering it’s performance retaliative to other Sata drives.