Page 2 - A Closer Look, Installation, Test System
Since there probably is not too much we can write about a solid state drive -- especially when it comes to the physical aspect of it -- let us quickly cover it before we move onto the technical aspects and benchmark results. The OCZ Synapse is pretty much identical in appearance to every other OCZ drive we have reviewed in the past, with the exception of the sticker in the middle now modified to reflect this change. It features an aluminum housing to enhance heat dissipation, with a side benefit of being incredibly lightweight for what you get. On top of the textured matte black finish is a large label across the center to ensure the user will make no mistake that this is an OCZ Synapse drive. Measuring in at 99 x 69.9 x 9.1mm, these are pretty much standard dimensions for a 2.5" internal drive. It is also quite lightweight, with a manufacturer's specification of 79g. OCZ Synapse 64GB drives will have no problems fitting into your laptop hard disk bay as a cache disk for your hard drive if it has multiple bays, but chances are that the Synapse will end up in your desktop. If your chassis has no 2.5" mount, a 3.5" adapter bracket is included right out of the box, so you can easily install this SSD in any standard desktop internal drive bay. This makes the Synapse quite convenient to deploy in either environments for the end user. My only complaint is that the screw holes on the 3.5" adapter bracket is slightly smaller compared to the ones found on standard 3.5" hard drive, so if you need to use any other screws other than the ones provided by OCZ (Such as, if your are installing the Synapse into a 3.5" drive bay that require screws provided by your chassis manufacturer due to use of vibration dampeners) then you will need to find your own solution.
Turning the SSD around reveals a familiar metal backplate -- except this time, there is no exposed printed circuit board like you would normally see with a traditional hard disk drive. The only thing that is common between the Synapse caching SSD and a traditional hard disk drive is its SATA 6Gb/s and its corresponding power connector at the end. As shown in our photo above, you will find a large label with the usual series certification logos and warning statements, along with information on drive model, capacity, serial number, and part number. The smaller adjacent label has the Dataplex license key printed on it, as shown in our photo above. As with all OCZ SSDs, they are all made in Taiwan, and this one is no exception.
The OCZ Synapse 64GB's shell is attached to the metal backplate by four small screws. One of the screws has a warranty seal over it, so in order to take a peek inside the caching SSD, you will have to inevitably void your warranty. Therefore, to save you some trouble, I cracked mine open to take some photos of its internals for you to see. It is really nothing complicated -- just a small OCZ designed green printed circuit board, and that's it. Of course, there is more than what that meets the eye. The heart of OCZ's Synapse 64GB is the SandForce SF-2281 controller. As the drive controller is fundamentally very important to any SSD, what makes it so special is that it is capable of doing real time data compression to make extremely fast I/O performance possible without the need of external cache memory.
The second generation SandForce controller used in the OCZ Synapse 64GB has been updated in several areas. Other than the obvious performance increases -- we will have lots of time to talk about that in just a second -- major updates include on-the-fly data encryption using a 256-bit AES algorithm, rather than an 128-bit AES algorithm by its predecessor. This cannot be disabled, but it lacks a password by default; it therefore functions as an unencrypted storage unit to the end user. As with the SF-1222, the SF-2281 also focuses on increased wear performance as part of the DuraWrite scheme. This has also been updated with better Error Correcting Code, or ECC. In the past, SandForce controllers used the Reed-Solomon algorithm -- it works well for correcting scattered errors, but has a high processing overhead, and therefore does not work very well for correcting concentrated errors. To overcome this problem, it is replaced by the Bose-Chaudhuri-Hocquenghem algorithm. Other than improved efficiency due to its straightforward implementation, it also works well in correcting both scattered and concentrated errors across the drive.
SandForce's DuraWrite system is especially beneficial to multi-level cell (MLC) based flash drives like the OCZ Synapse. Unlike single level cell (SLC) flash memory, MLC flash memory stores four states, or two bits, per cell. It is cheaper to manufacture; unfortunately it also has significantly less write cycles before it wears out -- not to mention flash memory comes in different grades. There are two main ways to resolve this problem. The first one is to use a technique called wear leveling. Wear leveling manages data in a way that erasures and rewrites are evenly spread out across the drive, so not a single area experiences a high concentration of write activity. Secondly, unlike traditional magnetic hard drives, data cannot be directly overwritten in the world of flash memory. The write area must first be erased before new information can be written. This brings onto the topic the second technique, which relates to a phenomenon called write amplification. Write amplification is calculated by the data written to the flash memory divided by the data written by the host. Optimally, you will want this number as low as possible -- and it is probably makes sense to think the lowest value possible is 1. That is, until the SandForce controller rolled along earlier this year and changed the rules of the game. By doing on-the-fly compression, this results in a write amplification of an astonishing low value of 0.5 according to the company. Intel SSDs have a write amplification of 1.1, and magnitudes as high as 10 are not out of the ordinary in the industry.
As aforementioned, pages of flash memory need to be first erased before it can be written to again. Traditional magnetic hard drives do not exhibit this characteristic, so normally when you hit the delete button, the operating system simply marks the corresponding data blocks as free with the data still physically intact. All this means is new data is permitted to overwrite existing data in that area. This poses a problem for solid state drives, because it will significantly decrease write performance if the user needs to wait for the system to clear an area before new data can be written. With native TRIM support, it allows the operating system to tell the SSD which blocks of data are no longer needed. The SSD can then do garbage collection overhead, and make it available for new data to be directly written without delay. I am not entirely sure if this feature is applicable in the context of a caching SSD directly, since the Synapse is going to operated almost exclusively by the Dataplex software, and invisible to the end user in the operating system.
Lastly, the new SandForce SF-2281 controller has updated toggle-mode and ONFi 2.2 flash memory support in conjunction with processor power throttling. The former improves compatibility with different flash memory for improved NAND supplier flexibility for the drive manufacturer; whereas the latter increases power efficiency like SpeedStep on your desktop CPU. All in all, the SandForce SF-2281 controller does have a small microprocessor and a few undisclosed megabytes of memory inside to handle all the dirty work -- but with the elimination of the external cache, SandForce based SSDs have unprecedented random read and write performance. This adds on to the already excellent sequential data rates across the board makes it a winning combination -- but we're not talking about just about just barely edging out SF-1222 drives in benchmarks. What we are talking about here is rated performance of a smashing 550MB/s max read, 490B/s max write, and up to 80,000 input/output operations per second. That's pretty much almost doubling the preceding generation's performance at neck breaking, pants peeing speed. Oh yeah, you will need a SATA 6Gb/s port, and you will want a native Intel one while we are at it.
A total of 8 NAND flash chips are found on the OCZ Synapse 64GB caching solid state disk. The chips used are Micron 29F64G08CBAAA asynchronous flash memory, with a capacity of 8GB per integrated circuit chip. These are multi-level cells manufactured on the 25nm fabrication process. 32GB out of the 64GB total capacity is provisioned for the SandForce drive controller for garbage collection and wear leveling algorithms, so the actual capacity used for caching is 32GB. With the Dataplex software installed, everything will be invisible in Windows. This is a very large amount compared to other SandForce based SSDs; which can range anywhere from 7% to 28% for what the company refers to as Redundant Array of Independent Silicon Elements, or RAISE. SandForce claims RAISE is similar to a RAID 5 array within the drive that redundant data can be used to recover entire pages of corrupt or lost data within the drive, should problems arise with its memory cells over time. This is implemented in conjunction with a powerful error correction system and cyclic redundancy check protection to improve its uncorrectable bit error rate. This is very crucial for a caching SSD, considering the data on the drive can change quite often.
For testing, we have paired the OCZ Synapse 64GB caching SSD with an old school Seagate Barracuda 7200.10 320GB HDD. A copy of Windows 7 Professional was installed on the hard drive; Dataplex (The program that works its magic) was then obtained from OCZ's website. After plugging in my license key found at the bottom of the Synapse, I was pleasantly surprised to discover the Dataplex software was only a few megabytes large. A quick note, the program requires activation, so if you want to move your caching drive to another computer, you must uninstall Dataplex from the initial computer first. The program works by automatically caching frequently accessed data onto the SSD invisibly in the background. As such, it will work with RAID arrays, and if your Synapse dies, you will not use any actual data. I have noticed no significant increased CPU load during testing either, which is awesome. And no, you certainly don't need a Z68 motherboard for this to work -- the only requirement is a computer with Windows 7 installed (That's Windows 7 exclusively -- you can't use it with Windows Server 2008 R2), and the Synapse paired up with the boot drive. For best performance, a native SATA 6Gb/s port is highly recommended.
Our test configuration as follows:
CPU: Intel Core i5-2405S
CPU Cooling: Thermaltake Frio (Noctua NF-P12)
Motherboard: ASUS P8P67 PRO
RAM: Kingston HyperX KHX1600C9D3X2K2/8GX 2x4GB
Graphics: Gigabyte Radeon HD 6870 1GB SOC
Chassis: Lian Li PC-Z60 (Noctua NF-S12B ULN)
Power: FSP AURUM CM Gold 650W
Sound: Auzentech X-Fi Bravura
Operating System: Microsoft Windows 7 Professional x64 SP1
Compared Hardware:
- OCZ Synapse 64GB and Seagate Barracuda 7200.10 320GB
- G.SKILL Phoenix EVO 115GB
- Kingston HyperX 120GB
- OCZ Agility 3 240GB
- OCZ Vertex 2 160GB 25nm
- OCZ Vertex 2 60GB 34nm
- OCZ Vertex 3 Max IOPS 240GB
- Patriot Pyro 120GB
- Western Digital Caviar Blue AAKS 500GB
Page Index
1. Introduction and Specifications
2. A Closer Look, Installation, Test System
3. Benchmark: AIDA64 Disk Benchmark
4. Benchmark: ATTO Disk Benchmark
5. Benchmark: Crystal Disk Mark 3.0
6. Benchmark: HD Tach 3.0.1.0
7. Benchmark: HD Tune Pro 4.60
8. Benchmark: PassMark PerformanceTest 7.0
9. Benchmark: PCMark Vantage
10. Conclusion
