OCZ Agility 60GB SSD (SLC)

Introduction

SSD's come in a lot of flavors and capacities but they only come in two basic types. Single level cell and Multi-Level cell. Multi-Level cell SSD's store two bits of information per cell and are less expensive. The storage of 2 bits of information in each Nand flash cell is harder on the drive and typically each cell can be written and erased 10,000 times. Multi level cell SSD's still last a good long time and provide up to 10 years static storage without power running to the drive. They take a little longer to write because of the complexity of writing two bits of information to one cell.Single level cell SSD's only write one bit of information to each cell and they are considered enterprise class drives and have a much longer longevity. They also write faster because of the simplicity of writing one bit of information to each cell. How much longer do they last you ask, well like we mentioned typical MLC drives write and erase each cell approximately 10,000 times, Single level cell drives write and erase each cell up to 100,000 times. Hence our deduction that Single level cell SSD's can have 10 times the longevity of MLC drives. That longevity comes at a premium price but it's not ten times more for a SLC drive than a MLC drive.

The OCZ Agility EX 60GB drive we are looking at today runs about $400 so they are pricey drives. That works out to $6.67 per Gigabyte of storage which is expensive compared to ordinary platter drives. Take your run of the mill 500GB platter drive which can easily be found for about $59.99 for a 7200 RPM 16MB cache drive, those run about $0.11 a gigabyte. The platter drives tend to run in the 60 - 70MB/s range and most end users settle for that and are happy with the considerable savings.

Not everyone is a typical end user. Blade and other servers depend on rack after rack of very expensive power hungry hard drives. Most are mission critical servers that have to have the utmost in dependability and speed. Enter what has become to be known in the industry as Enterprise class drives. The first Enterprise class drives that we saw were platter based drives and ran about 30MB in size, 30MB ran about $269 and dependability was spotty. Way down the line after the Dinosaurs died off we started seeing SCSI drives that ran up to 10K RPM and had higher platter density.

SCSI or Small Computer Serial Interface drives could daisy chain 8 synchronized platter drive on a chain of up to 8 drives. The higher platter density meant that the physical hard drive read heads had to travel less distance to fetch information and the 10k RPM drive speed meant that it got there faster. However imagine rack after rack of SCSI drive generating heat and pushing the power bill ever higher. We've worked on SCSI racks and the noise and heat on a 48 drive rack can be considerable, not to mention the failure rate and expense of powering all those drives.

Now imagine those same hundred drives converted to reliable enterprise class SSD's sipping a mere fraction of a watt (.5w idle 2w active) per drive, with no moving parts, and a minimum of heat, designed to last 100,000 write/erase cycles. Then when they do decide to fail the firmware on the drive will stop allowing the data to be written on the drive and revert to a read only state. That's a server farm operators dream come true.

Well now the average end user can have Enterprise class storage in their desktop, OCZ has the EX series drives and we are going to take a look at the OCZ Agility EX 60GB SSD. Designed with the Indilinx Barefoot controller found in most of OCZ's offerings it's by far our favorite controller. Seated in the Agility EX drive it can push the Nand flash up to 255MB/s read and 195MB/s write (100MB/s sustained write).

The OCZ Agility SLC 60GB drive promises great performance and excellent longevity. With the read speed advertised at up to 255MB/s and the write speed up to 195MB/s we expect big things from the Agility EX SSD. How OCZ managed to squeeze all that speed into this little package, and do it with the most affordable 60GB SLC SSD we've seen is a mystery to us. Being the least expensive 60GB SLC around is sure to make it a popular choice amoung the most demanding enthusiasts.