Pliant Claims 2.3 Million IOPS With Lightning SSD

Pliant Technology has released the results of independent testing, indicating that its Lightning family of Enterprise Flash Drives (EFDs) can reach 2.3 million I/O operations per second (IOPS). This suggests that data centers using the drives in their servers could see significantly faster performance than with competing drives. The Lightning line, which consists of a 2.5-inch and two 3.5-inch drives, has been shipping since September to licensees, says product manager C.T. Chu, though he refrained from naming them.

The 2.3 million IOPS figure is based on 100 percent reads of 512KB blocks. "This particular drive is 2 to 2.5 times better than anything I've seen," says Bob Weisickle, CEO of Oakgate Technology, an independent company paid by Pliant to perform the tests with its FireOak tool. Such drives would be particularly useful in data-intensive operations such as online transaction processing, database applications and image rendering, Weisickle says. A real-world, datacenter testing configuration, with an 80/20 read/write ratio using 4KB blocks, resulted in 1.1 million IOPS, according to the tests.

The 2.5-inch drives are 150GB, while the 3.5-inch drives are 300GB and 150GB. The Lightning drives cost between $20 to $30 per Gb, which the company says is comparable to similar SSD products from STEC and Intel. While disk drives cost $2 to $3/GB, they have much lower performance and higher power and cooling, compared to SSD, which has much higher performance with lower power and cooling requirements, resulting in a lower total cost of ownership, the Pliant says. To produce the same level of IOPS hard disks would require thousands of drives, requiring more floor space and power, Weisickle says.

Pliant's Lightning drives are faster than most other SSDs because they use the serial attached SCSI (SAS) interface, while most other SSDs use the serial ATA (SATA) interface. While SATA is typically single duplex, meaning it can read or write but not both simultaneously, SAS is dual-port and offers two full-duplex paths to the drive, so it can both read and write data at the same time.

In addition, most SSDs have a drop in performance after some use and are limited in the number of writes per day they should perform to keep that performance, Chu says. The Lightning drives are an order of magnitude more reliable than most other hard drives in terms of their unrecoverable bit error rate, and they use a proprietary architecture that keeps them from having that performance drop. "There's always the fine print of how many writes per day you're allowed to do," Chu says. "We don't have that limitation." Weisickle confirms that the Lightning drive performance remained more stable and consistent than comparable drives. "With many SSDs, if you run this level of read/write traffic, performance could be half of what it was when you started," he says.