Micron just announced a new SSD drive based on their 34nm SLC NAND technology with some pretty impressive performance numbers. They used an independent organization, Calypso SSD testing, to supply the performance numbers:
- Random Read 44,000 IO/sec
- Random Writes 16,000 IO/sec
- Sequential Read 360MB/sec
- Sequential Write 255MB/sec
Even more impressive considering this performance was generated using SATA 6Gb/s and measuring after reaching “SNIA test specification – steady state” (see my post on SNIA’s new SSD performance test specification).
The new SATA 6Gb/s interface is a bit of a gamble but one can always use an interposer to support FC or SAS interfaces. In addition,today many storage subsystems already support SATA drives so its interface may not even be an issue. The P300 can easily support 3Gb/s SATA if that’s whats available and sequential performance suffers but random IOPs won’t be too impacted by interface speed.
The advantages of SATA 6Gb/sec is that it’s a simple interface and it costs less to implement than SAS or FC. The downside is the loss of performance until 6Gb/sec SATA takes over enterprise storage.
P300’s SSD longevity
I have done many posts discussing SSDs and their longevity or write endurance but this is the first time I have heard any vendor describe drive longevity using “total bytes written” to a drive. Presumably this is a new SSD write endurance standard coming out of JEDEC but I was unable to find any reference to the standard definition.
In any case, the P300 comes in 50GB, 100GB and 200GB capacities and the 200GB drive has a “total bytes written” to the drive capability of 3.5PB with the smaller versions having proportionally lower longevity specs. For the 200GB drive, it’s almost 5 years of 10 complete full drive writes a day, every day of the year. This seems enough from my perspective to put any SSD longevity considerations to rest. Although at 255MB/sec sequential writes, the P300 can actually sustain ~10X that rate per day – assuming you never read any data back??
I am sure over provisioning, wear leveling and other techniques were used to attain this longevity. Nonetheless, whatever they did, the SSD market could use more of it. At this level of SSD longevity the P300 could almost be used in a backup dedupe appliance, if there was need for the performance.
You may recall that Micron and Intel have a joint venture to produce NAND chips. But the joint venture doesn’t include applications of their NAND technology. This is why Intel has their own SSD products and why Micron has started to introduce their own products as well.
So which would you rather see for an SSD longevity specification:
- Drive MTBF
- Total bytes written to the drive,
- Total number of Programl/Erase cycles, or
- Total drive lifetime, based on some (undefined) predicted write rate per day?
Personally I like total bytes written because it defines the drive reliability in terms everyone can readily understand but what do you think?