The Kingston SSDNow is a new line of affordable enterprise SSDs that recently came out. We tested the 240 GB model.
It took a while for the enterprise market to embrace SSDs, but they're finally becoming more common. The advantage of the fast storage medium can benefit server workloads. Kingston would like the new E50 SSDs to be an affordable replacement for 10k or 14k rpm conventional hard disks. They're intended for read intensive workloads, which means they're not optimised for high endurance workloads in which SSDs are under continuous workloads. The new E50 SSD is significantly more affordable than other enterprise SSDs such as the Intel DC S3700 series. The SSNow E50 240GB we tested costs an average of € 1.20 per GB, where € 2 or more per GB is typical for enterprise SSDs.
The SSDNow E50 is built around the LSI SandForce SF-2581 controller, the enterprise version of the popular SF-2281 used in many consumer SSDs. The SF-2581 has gone through many more compatibility and validation tests for servers and server workloads. The controller has an MTBF of 10 million hours, compared to 2 million for the SF-2281. The SF-2581 features advanced SMART diagnostics, which gives system administrators detailed monitoring capabilities. The biggest difference with the consumer version is that the SF-2581 can be combined with powerful capacitors that contain enough power in case of an outage to store all buffered data in the flash memory.
Kingston implemented that last feature in the E50 and to this end a large number of so-called tantalum capacitors are found on the PCB. Kingston guarantees that all data that's written to the SSD via the SATA bus will be written to the flash memory when it loses power.
The other aspects of the SF-2581 are identical to the SF-2281, which means it also does data compression and data deduplication and that it will perform better with compressible data, limiting the write amplification factor in those cases.
The flash memory is Toshiba 19mn ToggleFlash NAND chips with a lifespan of more than 3000 p/e cycles. For read intensive workloads that's fine, but it's of course less than enterprise SSDs made for endurance (and therefore write intensive workloads).
The SSDNow E50 is available in three capacities: 100 GB, 240 GB and 480 GB. The 240 GB model we tested has indicated read speeds of 550 MB/s and a maximum write speed of 530 MB/s. The typical 4k random speeds are 48,000 IOPS for reading and 72,000 IOPS for writing. And as we've seen before with SandForce drives, the 480 GB has lower write speeds.
Kingston says the drive supports three complete drive writes per day. Combined with the three-year warranty it means the 240 GB model is guaranteed for 739TB of writes and that the flash chips offer 3 x 3 x 365 = 3285 p/e cycles.
|Kingston SSDNow E50||100 GB||240 GB||480 GB|
|Seq. Read||550 MB/s||550 MB/s||530 MB/s|
|Seq. Write||530 MB/s||530 MB/s||500 MB/s|
|Random 4k Read||27000 IOPS||48000 IOPS||53000 IOPS|
|Random 4k Write||82000 IOPS||72000 IOPS||32000 IOPS|
|Total Bytes Written||310 TB||739 TB||1747 TB|