CeBIT overnight testing - OCZ Vertex 2 Pro SSD - Sandforce, pt.2, setup
Author: Vedran Dakic
Date: 04 Mar 2010

"The SF-1200 Mobile SSD Processors provide data protection that surpasses the leading high-performance enterprise HDDs used today. This comes from a combination of superior ECC algorithms with up to 24 bytes protection and the unique RAISE™ (Redundant Array of Independent Silicon Elements) technology. RAISE provides the protection and reliability of RAID on a single drive without the 2x write overhead of parity. This capability is transparent to the end-user and provides peace-of-mind for mobile SSD OEMs knowing their customer’s data is protected."

One thing that Sandforce worked heavily on is write amplification, as clearly stated on their website. This is something that regularly happens on SSD's, and the definition goes something like this: " Write amplification is a measurement of additional P/E cycles that must be executed on the flash interface to get data programmed into the flash and in this equation, also takes into account inefficiencies due to wear leveling".The idea behind this is to reduce the amount of data being written to the disk by reducing write amplification, which is something that DuraClass technology takes care of. It reduces the write amplification by a factor of (up to) 20x.

The reason why Sandforce-based drives don't use additional DRAM cache is also a simple one. Traditional SSD's use DRAM cache to "organize and consolidate" writes before they are actually written to SSD's flash memory. Considering what we already discussed about DuraClass, it becomes apparent that DRAM cache is just - not needed. It also reduces the number of devices on SSD, drives the cost down and simplifies the design. Also, Sandforce looked into the basic SSD problem - reduced write performance that comes with SSD being used over a longer period of time. The thing is that SSD's, unlike HDD's, have to erase the whole block before writing to it again, and keep track of the whole process at the same time. The term commonly used even in programmer's world is - garbage collection. DuraWrite and DuraClass take care of this particular problem.

So far so good? OK, let's move on to performance. We've used a Core i5 testbed to test this SSD, consisting of:
- Gigabyte GA-P55-UD5
- Intel Core i5 750
- OCZ PC3-10666 CL7 2x2GB memory (Core i5 kit)
- WD RaptorX 150GB
- Sapphire Radeon HD4890
- Samsung 2433LW LCD display
- OCZ ProXstream 1kW power supply unit

Let's check out the results.