AkG
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Last year Crucial's MX100 series introduced 128GBit 16nm MLC NAND to the marketplace and ultimately redefined the meaning of 'value' orientated SSDs. While there may have been some compromises in terms of sheer performance, the MX100’s durability, capacity and overall price was only matched by Samsung's TLC equipped drives. Even now, nearly a year after its launch, Crucial’s groundbreaking drives are still considered some of the best around.
The MX200 series is the newest addition to Crucial’s lineup and it is targeting a slightly more mainstream market. It is essentially supposed to replace the MX100 and M550 series while the entirely new budget 'BX100' series hits up a lower price point(expect a review of the BX100 soon!). While the MX200 supposed to take over from the MX100, its combination of 16mm 128GBit MLC NAND with a Marvell 9188 controller backstopped by extremely aggressive pricing makes this new mainstream series one serious competitor for the likes Samsung's 850, OCZ Vertex 460, and a whole host of other drives.
To keep with its aggressive pricing roots, the MX200 will be priced at $140, $250, and $470 for the 250GB, 500GB and 1TB models respectively. This range of prices puts it within grasp of most buyers while anyone who wants a true budget SSD should gravitate towards the BX100.
The MX200 is much more than a pretty face and some fancy specifications since there have been some feature-centric advances as well. Starting out at a high level, there’s MLC NAND, AES-256 encryption and Dynamic Write Acceleration, a technology that is found on some datacenter-class SSDs but is now being rolled into these new drives. It is supposed to drastically improve file transfers and the speed at which the SSD writes files to its NAND.
There are also a number of advanced additions like Exclusive Data Defense which guards against corrupt files, a new Adaptive Thermal Protection design for improved component cooling and Power Loss Protection which is supposed to protect against data loss in the event of a power interruption. Many of these were normally found on more expensive workstation and enterprise SSDs in the past but it looks like they are finally starting to trickle down into the home user market.
By combining a fast controller with advanced NAND and a bevy of bandwidth enhancements Crucial has been able to achieve sequential reads and write up to 555MB/s and 500MB/s, along with random reads and writes up to 100k and 87k IOPS on all file types. Also, the 1TB model has an endurance rating of up to 320 TBW.
Externally the new MX200 series look almost exactly like both the M550 and MX100 series before it. As with those Crucial models, the MX200 uses a full metal enclosure that uses the smaller 7mm Z-height 2.5” form-factor. This in conjunction with the included 2.5mm plastic spacer allows the MX200 to fit inside everything from UltraBooks to notebooks. Unfortunately, Crucial still does not include a 3.5" adapter plate, so installing inside a full size PC chassis may require purchasing this accessory separately. Luckily, most new cases come with 2.5" SSD mounting capabilities, and for those that don't, the adapters are only a few dollars. A full copy of Acronis True Image is included as well.
The MX200’s innards nearly mirror the layout seen on the MX100; there are 8-16 NAND ICs (eight for the 500GB, sixteen for the 1TB), 256-512MB worth of RAM cache (1 IC for 500GB, 2 IC for 1TB), and a Marvell '9188 controller. On first blush this does pose the question on what Crucial actually done to improve performance and justify moving this MX200 up from the initial MX100's more value-oriented positioning.
The real changes have been applied beyond what we’re able to see. Instead of simply using a more powerful controller, or other similar tricks that have been the de rigueur methods of separating seemingly similar models in the past, Crucial has instead opted for a more firmware based approach. Put simply the controller can use a portion of the NAND to act in quasi SLC mode to cache write IOs, and during slow periods then write the 'cache' to NAND tasked for standard MLC mode.
This quasi SLC mode is what Crucial calls Drive Write Acceleration and it significantly boosts write performance of these MLC NAND modules. As an added benefit DWA also increases write endurance - up from 72TB to 320TB in the 1TB model. While Crucial is not the first to use this hybrid caching method, their implementation is actually one of the most impressive.
Unlike Samsung the portion of NAND which can be used in quasi-SLC mode can be increased or decreased based on the usage pattern the individual controller encounters and how much free space the controller has to work with. Instead of simply dedicating an arbitrary about of NAND for caching Crucial's DWA uses up to 50% of the free capacity for SLC write caching.
Unfortunately 'DWA' does cost the drive capacity so for every Gigabyte of MLC NAND used in 'SLC' Mode, the drive has to dedicate two Gigabytes worth of NAND. This is why the MX200’s capacities are smaller than the MX100 series. In addition the NAND used in quasi-SLC mode is only for cache purposes and once the I/Os drop, all permanent data is then internally written to the 'slower' MLC NAND. If the write IOs continue the drive will start copying from SLC to MLC to free up space in real-time. This could potentially cause major slowdowns compared to non-DWA models, but these drives are not meant for servers where the I/O operations are continuous.
While this also technically doubles the total number of writes, in reality most writes to an SSD are temporary in nature and thus the amount of data that needs to be written to the MLC NAND modules is drastically reduced. More importantly the NAND working in SLC mode is much less fragile and can be written to significantly more times before 'breaking'.
On paper at least, DWA will do very little to boost performance for large capacity models but it should benefit slower, lower capacity drives. This is why even the smallest 250GB boasts performance very similar to that of its larger brethren, something the MX100 series could never do. In fact, for the larger capacity models the potential negatives actually outweight the potential gains. For this reason, DWA is supposedly not active on these larger 512GB and 1TB models - and only the 250GB model is confirmed to have DWA activated.
Despite its lack of DWA, the 1TB model does boast twice the onboard cache compared to the MX100 series and all MX200 drives boast TCG Opal 2.0, eDrive encryption, DevSleep, and Flush in Flight capabilities. As an added bonus they also now include enhanced Thermal Protection capabilities that will lower the operating speed of the drive if it is reaching critically high temperatures. This will be of limited to value to most customers but it is another layer of protection against sudden - and catastrophic - drive failure. Whether or not all these features are enough to justify this new series slightly higher price per Gigabyte remains to be seen.
The MX200 series is the newest addition to Crucial’s lineup and it is targeting a slightly more mainstream market. It is essentially supposed to replace the MX100 and M550 series while the entirely new budget 'BX100' series hits up a lower price point(expect a review of the BX100 soon!). While the MX200 supposed to take over from the MX100, its combination of 16mm 128GBit MLC NAND with a Marvell 9188 controller backstopped by extremely aggressive pricing makes this new mainstream series one serious competitor for the likes Samsung's 850, OCZ Vertex 460, and a whole host of other drives.
To keep with its aggressive pricing roots, the MX200 will be priced at $140, $250, and $470 for the 250GB, 500GB and 1TB models respectively. This range of prices puts it within grasp of most buyers while anyone who wants a true budget SSD should gravitate towards the BX100.
The MX200 is much more than a pretty face and some fancy specifications since there have been some feature-centric advances as well. Starting out at a high level, there’s MLC NAND, AES-256 encryption and Dynamic Write Acceleration, a technology that is found on some datacenter-class SSDs but is now being rolled into these new drives. It is supposed to drastically improve file transfers and the speed at which the SSD writes files to its NAND.
There are also a number of advanced additions like Exclusive Data Defense which guards against corrupt files, a new Adaptive Thermal Protection design for improved component cooling and Power Loss Protection which is supposed to protect against data loss in the event of a power interruption. Many of these were normally found on more expensive workstation and enterprise SSDs in the past but it looks like they are finally starting to trickle down into the home user market.
By combining a fast controller with advanced NAND and a bevy of bandwidth enhancements Crucial has been able to achieve sequential reads and write up to 555MB/s and 500MB/s, along with random reads and writes up to 100k and 87k IOPS on all file types. Also, the 1TB model has an endurance rating of up to 320 TBW.
Externally the new MX200 series look almost exactly like both the M550 and MX100 series before it. As with those Crucial models, the MX200 uses a full metal enclosure that uses the smaller 7mm Z-height 2.5” form-factor. This in conjunction with the included 2.5mm plastic spacer allows the MX200 to fit inside everything from UltraBooks to notebooks. Unfortunately, Crucial still does not include a 3.5" adapter plate, so installing inside a full size PC chassis may require purchasing this accessory separately. Luckily, most new cases come with 2.5" SSD mounting capabilities, and for those that don't, the adapters are only a few dollars. A full copy of Acronis True Image is included as well.
The MX200’s innards nearly mirror the layout seen on the MX100; there are 8-16 NAND ICs (eight for the 500GB, sixteen for the 1TB), 256-512MB worth of RAM cache (1 IC for 500GB, 2 IC for 1TB), and a Marvell '9188 controller. On first blush this does pose the question on what Crucial actually done to improve performance and justify moving this MX200 up from the initial MX100's more value-oriented positioning.
The real changes have been applied beyond what we’re able to see. Instead of simply using a more powerful controller, or other similar tricks that have been the de rigueur methods of separating seemingly similar models in the past, Crucial has instead opted for a more firmware based approach. Put simply the controller can use a portion of the NAND to act in quasi SLC mode to cache write IOs, and during slow periods then write the 'cache' to NAND tasked for standard MLC mode.
This quasi SLC mode is what Crucial calls Drive Write Acceleration and it significantly boosts write performance of these MLC NAND modules. As an added benefit DWA also increases write endurance - up from 72TB to 320TB in the 1TB model. While Crucial is not the first to use this hybrid caching method, their implementation is actually one of the most impressive.
Unlike Samsung the portion of NAND which can be used in quasi-SLC mode can be increased or decreased based on the usage pattern the individual controller encounters and how much free space the controller has to work with. Instead of simply dedicating an arbitrary about of NAND for caching Crucial's DWA uses up to 50% of the free capacity for SLC write caching.
Unfortunately 'DWA' does cost the drive capacity so for every Gigabyte of MLC NAND used in 'SLC' Mode, the drive has to dedicate two Gigabytes worth of NAND. This is why the MX200’s capacities are smaller than the MX100 series. In addition the NAND used in quasi-SLC mode is only for cache purposes and once the I/Os drop, all permanent data is then internally written to the 'slower' MLC NAND. If the write IOs continue the drive will start copying from SLC to MLC to free up space in real-time. This could potentially cause major slowdowns compared to non-DWA models, but these drives are not meant for servers where the I/O operations are continuous.
While this also technically doubles the total number of writes, in reality most writes to an SSD are temporary in nature and thus the amount of data that needs to be written to the MLC NAND modules is drastically reduced. More importantly the NAND working in SLC mode is much less fragile and can be written to significantly more times before 'breaking'.
On paper at least, DWA will do very little to boost performance for large capacity models but it should benefit slower, lower capacity drives. This is why even the smallest 250GB boasts performance very similar to that of its larger brethren, something the MX100 series could never do. In fact, for the larger capacity models the potential negatives actually outweight the potential gains. For this reason, DWA is supposedly not active on these larger 512GB and 1TB models - and only the 250GB model is confirmed to have DWA activated.
Despite its lack of DWA, the 1TB model does boast twice the onboard cache compared to the MX100 series and all MX200 drives boast TCG Opal 2.0, eDrive encryption, DevSleep, and Flush in Flight capabilities. As an added bonus they also now include enhanced Thermal Protection capabilities that will lower the operating speed of the drive if it is reaching critically high temperatures. This will be of limited to value to most customers but it is another layer of protection against sudden - and catastrophic - drive failure. Whether or not all these features are enough to justify this new series slightly higher price per Gigabyte remains to be seen.
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