The SSDs: 16 x Samsung 470 (256 GB)
We used drives from Samsung's 470 series, also known as PM810 (OEM product name), for testing. Because of their SATA 3 Gb/s interfaces, these devices don't reach the random I/O of OCZ's latest drives, or the sequential throughput of Intel's SSD 510. Nevertheless, the Samsung drive still offers consistent performance: in our tests, it demonstrated constant throughput, regardless of the workload or the application. Moreover, it did not show any significant weaknesses. Therefore, the Samsung 470 is a respectable choice for testing the potential of a RAID array. Just bear in mind that these are MLC-based SSDs, so they're not going to be your best option for enterprise-oriented applications (especially in RAID 0).
The tests also showed that 16 SSDs with 6 Gb/s interfaces wouldn't have improved the overall throughput performance of our RAID array. This is not a consequence of the SSDs we used, but more a reflection on the RAID controllers from LSI, which raised a white flag under the assault of our ambitious setup. The LSI MegaRAID 9260-8i and MegaRAID 9280-24i4e max out at 150 000 IOPS and allow a maximum data throughput of around 1600 MB/s each That's the ceiling we run into. According to the manufacturer, second-generation 6 Gb/s devices should more than double those numbers. We’ll validate the company's claims in an upcoming controller roundup.
The Samsung 470 series is based on the MAX controller (S3C29MAX), designed by Samsung, which employs eight channels, enables access to 256 MB cache, and supports 32-queue Native Command Queueing (NCQ). At about seven millimeters in height, these SSDs are thinner than most of their competitors, and therefore better-suited for installation in thin notebooks. Samsung offers the drives in 64, 128, and 256 GB capacities, and provided us with 16 256 GB devices for our tests. We operated the drives using firmware version 0701Q.
The drives used were the current OEM edition, which differ slightly from the retail models. The SSDs interior showed that Samsung chose a PCB format that would also fit in 1.8-inch drive designs. The flash devices are Samsung 30 nm toggle-mode DDR NAND modules, which work on double data rate mode, similar to system RAM.
