OCZ Vertex 4 SSD review
A closer look at the OCZ Vertex 4 SSD hardware
OCZ Vertex 4 SSD hardware.
Let’s take a closer look at the hardware.
OCZ Vertex 4 512GB SSD (PCB top-side)
On the top side of the PCB, we can see eight MLC NAND chip packages, and the first of two 512MB of SDRAM cache packages. We can also see what are thought to be channel muxing chips to provide optimum throughput to the NAND array.
OCZ Vertex 4 512GB SSD (PCB underside)
On the underside of the PCB we can see another eight NAND chips, the Indilinx Everest 2 controller, and the second 512MB of cache. Note the strange orientation of the Everest 2 controller. OCZ didn’t place it that way just to be different, and there are sound engineering principles why the controller is orientated in this fashion.
Placing the controller in the centre of the PCB and placing it at an offset angle allows the distance to each of the NAND chips to be minimised. The shorter the distance a signal has to travel, then the faster it will travel and will be less prone to picking up noise which then degrades the signal, as a degraded signal will then require greater error correction. So orientating the controller in this fashion has technical advantages.
Indilinx Everest 2 SSD platform controller.
Above we can see the brand new 400 series Indilinx Everest 2 SSD processor, designated IDX400M00-BC on the OCZ Vertex 4 series of SSDs.
Intel 25nm MLC NAND
The OCZ Vertex 4 series 512GB SSD has 512GB of Intel ONFI 2 synchronous MLC NAND onboard, with a life expectancy of 5000 P/E cycles, and a user capacity of 476GB.
Micron DDR3 SDRAM cache
Above we can see the cache chips that are fitted to the OCZ Vertex 4. They consists of two 800MHz DDR3 SDRAM chip packages manufactured by Micron, each chip has a capacity of 512MB giving a total of 1GB of cache. The cache provides a stable read and write buffer for the Everest 2 controller, and also provides space for things such as deferred writes, and other housekeeping tasks.
From the above specifications we can see that the 512GB is the fastest with the 256GB model not that far behind. The 128GB model has lower sequential write, but still enjoys excellent small file random performance.
From the “features” screenshot we can see that the warranty on the OCZ Vertex 4 has been increased to five years. This is up from the three years that was offered on the Vertex 3.
Advanced feature set
- Broadest NAND flash support, including 1xnm and TLC
- Up to 8 NAND flash channels with up to 16-way interleaving per channel
- Up to 535 MB/s transfer rates when using synchronous NAND
- HyperQueueing™ and Native Command Queuing (NCQ), with a queue depth up to 32 commands, and algorithms to optimize the order in which read and write operations are executed
- Up to 8Gb (1GB) of 800MHz DDR2/DDR3 DRAM cache support
- Multi-Level ECC with 128-bit correction capability per 1KB of data
- RNA Redundant NAND Array to protect against catastrophic NAND flash failure
- True end-to-end data path protection performs data integrity checks at every juncture where data is transmitted, received, processed and stored to ensure that corrupted data will be detected and not propagated
- Power fail protection and optional Supercap support prevents data loss in the event of a power failure
- Auto encryption and AES-256 encryption to protect and secure data
- Additional flash management techniques such as TRIM, background garbage collection, dynamic and static wear-leveling and advanced flash defect management
While not a lot is known about the inner workings of the Everest 2 controller, I can now tell you a little bit about Ndurance 2.
As NAND dies shrink, and costs drive manufacturers of NAND to squeeze evermore bits of data into a single NAND cell, then the endurance of the NAND takes a hit in the form of reduced write cycles. For this reason write amplification must be kept as low as possible. The SandForce answer to this was to compress data on the fly, thereby reducing the amount of data that had to be written to the NAND array. This solution is very effective at reducing write amplification, but the penalty for compressing data on the fly is reduced performance with data that can’t be compressed.
Ndurance 2 takes a different approach. It does not compress data, so there is no performance hit when reading or writing compressed data. Ndurance 2 technology uses a suite of advanced NAND flash management techniques, designed by Indilinx to work in tandem with the Indilinx Everest 2 SSD processor. The goal is to give consumer grade MLC NAND the same endurance as enterprise grade SSDs.
Ndurance 2 technology uses several different techniques to achieve this. For further clarification on how this works, the following paragraphs in (italic) were supplied by OCZ Technology.
“Advanced Multi Level ECC
Ndurance 2.0 features an advanced, multi-level ECC engine with progressive error correction capabilities that can adapt to the specific error characteristics of different NAND devices. By combining a flexible and programmable ECC engine with a sophisticated Flash Translation Layer (FTL), Ndurance 2.0 can achieve an effective correction power of up to 128 bits per 1KB of data, far exceeding the requirements specified for current and next-generation NAND flash devices while significantly reducing the uncorrectable bit error rate (UBER).
Adaptive NAND Management and Signal Processing
Ndurance 2.0 does not rely on advanced ECC methods alone to protect against data loss, but incorporates several capabilities to mitigate the actual sources of data corruption. It applies both proprietary and vendor-commands that such as internal voltage shifting and sophisticated signal processing techniques to extend the life of the NAND cell. As a result, Ndurance 2.0 minimizes the physical deterioration of NAND flash, reduces disturbances that affect adjacent flash cells, and improves physical data recovery capabilities, all of which maximize drive life.
Optional Redundant NAND Array™ (RNA) Technology
The optional RNA technology generates parity data information and stripes it across multiple NAND flash cells. The redundancy created by this block-level striping and distributed parity provides RAID-like protection that enables data to be divided and replicated amongst multiple NAND flash devices within the SSD. As a result, RNA safeguards against catastrophic NAND flash failures and uncorrectable data errors beyond what ECC covers, providing yet another mechanism for extending NAND flash life.
Reduced Write Amplification without Compression
Ndurance 2.0 additionally extends SSD life by reducing the actual number of programming operations to NAND flash without the need for performance-degrading data compression. To achieve lower write amplification, several proprietary methods are implemented that improve the efficiency of read-modify-write operations. By concatenating multiple write requests from the host and minimizing wasteful copy back operations of unaffected data sectors, excessive programming and read operations can be virtually eliminated, which in turn, preserves precious program/erase cycles.”
Thanks to OCZ Technology for providing this information.
Drive maintenance features
For Windows 7 users and some distributions of Linux, the OCZ Vertex 4 SSD supports ATA TRIM to keep the NAND clean. The Vertex 4 also has advanced garbage collection to clean the NAND during drive idle periods. You can also use the OCZ SSD toolbox to maintain the Vertex 4 series of SSDs.
OCZ SSD Toolbox
From the toolbox the user is able to monitor the SSD health status via SMART. You can also securely erase the drive, and update the drive’s firmware.
Note: To update the drive’s firmware, the drive needs to be connected as a spare, since Windows cannot flash a drive that is running the operating system. The same applies to secure erasing the SSD.
The OCZ SSD toolbox is functional, and it works very well indeed.
Let’s head to the next page where we take a look at our testing methods and the review PC.