The SSDs: Sixteen Intel X25-Es
Intel is in the process of ramping up its next generation of flash SSD drives, as all new products are based on 34 nm MLC flash (X25-M for consumers).
The X25-E drives should also be receiving an upgrade with the die-shrunk flash memory chips soon. Nevertheless, we kept the same drive lineup that we had used for the initial story: 16 X25-E enterprise-class flash SSDs from Intel with a capacity of 64 GB each. The total capacity of a fully-configured array with these 16 drives is exactly 1 TB, but capacity wasn’t our objective here. Rather, we wanted more throughput and better I/O performance.
The Intel X25 SSDs are all based on an in-house design with a 10-channel flash controller and integrated 16 MB cache memory. They have Native Command Queuing (NCQ) support, allowing the drives to optimize performance, manage wear leveling, and counter performance-degrading effects such as write amplification. In short, the SSDs continually optimize storage to maximize the user experience at all times.
None of the SSDs currently available support Serial Attached SCSI (SAS) or 600 MB/s transfer speeds, and it appears that a faster interface isn’t necessary--at least not yet. The drives we used are sufficient to reach 3GB/s+ throughput in RAID, but we believe they cannot actually saturate the new generation HBAs and RAID controllers utilizing PCI Express 2.0 and SAS/600.
