It’s impossible to mention the data storage market without at least hinting at the recent floods on Thailand, which managed to spoil many plans regarding shipped quantities and retail prices of HDDs. Yet it seems that luck is a wheel indeed. The lack and price hike of HDDs caused SSD manufacturers to hit the market with full force. Within six months, all SSD manufacturers refreshed and expanded their SSD offer. Besides the most expensive ones, more accessible models have been made available as well, but also hybrid versions which combine HDD and SSD technologies.
The concept of ultrabooks included SSDs exclusively, and even a good portion of regular notebook PCs now come with an SSD for caching data for the most frequently used applications. For those who find SSDs too expensive at the moment, there’s the option of hybrid drives, such as models from Seagate’s Momentus series, a combination of cheap low-capacity SSD and a standard HDD, interconnected via Intel’s RST or an additional cache drive. The model that we got for testing, however, is signed by OCZ, and responds to the name Synapse.
At first glance, this SSD isn’t very different from any other that we’ve had the opportunity to see. The standard 2.5” packaging contains a drive equipped with the most popular latest-gen controller, namely Sandforce, as well as 64 GB worth of memory. Sandforce SF-2281 is in control of eight 25 nm flash chips with a capacity of 8 GB each, with a little less than half (just under 30 GB) at disposal to the user, while the rest is used for caching. As you may already know, Sandforce SF-2281-based SSDs don’t have additional chips used as buffer memory and have to “steal” part of the total capacity by allocating, so these models actually come in capacities of 60 GB instead of 64 GB, 120 GB instead of 128 GB etc.
If we regard Synapse as a regular SSD, it’s a 30 GB disk that ranks among the very best in sequential read/write performance in its league, as it’s based on the SF-2281 controller and has high-quality NAND chips. This basically means around 500 MB/s read and 450 MB/s write speed, with a solidly high number of IOPS. Of course, SF-2281’s typical ailment in the form of worse performance with non-compressive data remains. On the other hand, Synapse was never intended to be a regular SSD, but more of a boost drive, which helps bring the speed of a regular HDD up to the level of an SSD. That’s why there’s as much as 30 GB “missing” from the SSD capacity, as Synapse uses it for data optimisation and caching, so it’s basically a drive with 30 GB of internal buffer.
Expectedly, Synapse is using the SATA III (6 Gbps) interface, and in order to give the drive caching functionality, you’ll need to install special NVELO Dataplex software, which can be found in the bundle. This piece of software is in charge of mapping Synapse as the cache drive and using it to speed up both the system core and the most frequently used applications.
The Dataplex software is simple to install, and the SSD itself has a licence sticker that needs to be entered when activating the software. Afterwards, the cache drive is linked to the HDD, and caching only works with the primary, system drive, which means that you can’t use Synapse for several drives at the same time (except when you have a RAID 0 system, which displays as a single HDD in the OS). After the SSD has been connected, only a single restart is needed to put caching in action. After the restart, Synapse is gone from the drive list, and the caching process is done completely automatically, independently from the user’s actions. When we say “independently”, we really mean it – the user is banned from any sort of intervention or setting as far as caching goes, which we dislike to a certain extent. It would be better if we could, for instance, pick applications that caching should focus on, personalising the process a bit, but that’s something that neither OCZ nor Dataplex want you to do.
We used a six-test battery to establish numbers for this SSD. SiSoft Sandra 2011 storage benchmark measures sequential read speed. We used WinRAR to compress the Windows 7 folder, which effectively measures compression acceleration, and since the Windows 7 folder has a huge wad of tiny files, it seems like the perfect choice for “torturing” an SSD. We also measure the time taken for a 5 GB file to be copied from one folder to the other, which should reflect performance you can expect when copying HD films and ISO files, i.e. the acceleration in the process. As far as games go, our choice fell on Crysis Warhead. We measured the time required to load a saved position, from the moment when “Load game” is clicked, as this action is highly dependent on fast access to the hard disk. We also created a 5 GB picture file and measured the time taken for Photoshop to load it (direct drive read) and save it to a new file after certain changes have been made through filters (again, direct drive write). Finally, there’s the inevitable Windows reset times, our VB script that measures the time needed for the Windows system to restart.
|Capacity/available [GB]||64 / 30|
|Controller||Sand Force SF-2281|
|Interface||SATA 6 Gb/s|
|Read/Writte speed [MB/s]||550 / 490|
|Other||NVELO Dataplex software|
||~ 90 EUR|
All tests were done five times, in order to allow Synapse to “learn” the applications and data being cached. The first testing system comprised testing rounds, when we ran one of each tests: Sandra, WinRAR, copying, Crysis, Photoshop and Windows 7 restart, in that order, before starting all over again. The second system also comprised five rounds, but with the same test being done five times in a row before switching to the next one.
It turns out that the second systems fleshed out the difference in performance offered by Synapse much better, but mostly because of the device’s limited capacity. With only 30 GB at disposal, Synapse just wasn’t able to cache all tests and data at the same time in order to make the first system viable. On the other hand, when the same test was repeated several times in a row, the drive handled everything much better, making the acceleration more tangible.
We couldn’t get any more details on the caching algorithm itself, as that sort of information is kept confidential both by OCZ and NVELO, but basically, from our experience, it uses all available capacity to copy the most used applications from the HDD to the SSD. We intentionally said “all available capacity”, because if you start five different games in a row, you shouldn’t expect the acceleration to be felt the next time you start the first game. There just isn’t enough data on the SSD to cache all the games at the same time, and the data from the first game will be replaced by subsequent data later on.
|Results||HDD||HDD + OCZ Synapse Pass 1||HDD + OCZ Synapse Pass 2||HDD + OCZ Synapse Pass 3||HDD + OCZ Synapse Pass 4||HDD + OCZ Synapse Pass 5|
|SiSiftSandra 2011 storage [MB/s]||100||81,2||301,5||301,4||300,7||300,9|
|WinRAR Windows 7 folder compression [s]||37,7||39,6||26,9||26,9||26,9||25,8|
|Big files 5 GB copy [s]||93,2||111,3||72,7||79,9||79,3||72,1|
|Crysis Warhead savegame [s]||42,9||40||21,7||21,7||21,7||21,7|
|Photoshop CS5 open/save 6 GB file [s]||59,8 / 52,7||56,9 / 14,1||18,3 / 14,1||18,3 / 14,2||18 / 14,1||17,9 / 14,1|
|Windows reset timer [s]||55||33||23||21||21||20|
|Intel Core i7 3860X, Sapphire Pure Black X79N (SATA 6 Gbps Intel X79), 4x 2 GB Kingston HyperX 2133 MHz DDR3, 500 GB WD Blue WD5000AAKS, AMD Radeon HD 7850, Windows 7 64 bit|
The guiding idea for OCZ was that you don’t need to buy expensive high-capacity SSD devices and then balance data all the time, deciding where to put which file etc. You can just take Synapse and pair it up with your regular HDD with a capacity of 1-2 TB, creating a hybrid drive that makes that sort of decisions automatically, as you’ll always have your most used applications cached. Just have a look at the results chart and you’ll see that acceleration is evident, ranging from 50% to 300%. The hybrid drive managed to raise performance from 100 MB/s to over 300 MB/s in SiSoft Sandra storage benchmark. Although compression is basically “home court” to Sandforce controllers, a lot of the files in the Windows folder just isn’t compressive, which makes acceleration less pronounced in this segment. We also came to realise that acceleration when copying large files also isn’t something you should count on very much. Synapse may cache a few files that you move around really frequently, but this is hardly a real-world scenario, so copying large files will likely yield the least advantage. On the other hand, disk access when loading a Crysis save or loading/saving a large file in Photoshop CS5 benefit greatly from a system such as this. Of course, the one thing that everyone uses frequently – system startup – caches best, bumping performance up to three times, which was both expected and pleasant to see.
According to our results, two or three runs of an application are sufficient to feel acceleration. Furthermore, you’ll already be experiencing maximum performance at third run, owing to the excellent algorithm, so further access to data and applications doesn’t have too much of an impact on performance, which is an excellent result.
The Synapse drive’s largest advantage compared to its direct competition – Intel RST (Rapid Storage Technology) – is that this SSD can work on any platform, as well as with an HDD of any capacity; RST is still limited in this latter regard. Just like with RST, drawbacks include the impossibility of software configuration, and at the moment, the lack of Linux support. The fact that Dataplex can only work with the system drive isn’t a flaw as such, as it’s the only logical usage scenario anyway. Perhaps the biggest issue with buyers opting for this system is the fact that a Synapse drive costs as much as a normal 64 GB SSD.
This brings us to the following dilemma. If you’re a user who doesn’t mind juggling data all the time to retain high performance, placing only the most critical data to the limited-capacity boot drive, then Synapse is definitely not the solution you should have in mind. However, if you want to turn your large HDD into a hybrid drive, OCZ Synapse does its work marvellously. The best thing about it is that it’s a very fast cache drive that isn’t too picky about the platform you’re using it with, which makes it available to AMD users as well, who can’t find the alternative in RST and similar technologies. Since SSD prices are dropping day by day, and Synapse still falls into this category, upgrading your existing storage system has probably never been more accessible in terms of price.