Random Read/Write Speed

The four corners of SSD performance are as follows: random read, random write, sequential read and sequential write speed. Random accesses are generally small in size, while sequential accesses tend to be larger and thus we have the four Iometer tests we use in all of our reviews. Our first test writes 4KB in a completely random pattern over an 8GB space of the drive to simulate the sort of random access that you'd see on an OS drive (even this is more stressful than a normal desktop user would see). I perform three concurrent IOs and run the test for 3 minutes. The results reported are in average MB/s over the entire time. We use both standard pseudo randomly generated data for each write as well as fully random data to show you both the maximum and minimum performance offered by SandForce based drives in these tests. The average performance of SF drives will likely be somewhere in between the two values for each drive you see in the graphs. For an understanding of why this matters, read our original SandForce article.

Desktop Iometer - 4KB Random Read (4K Aligned)

Random read performance has never been a strength of SandForce as even Intel SSD 320 outperforms most SandForce based SSDs. As the graph shows, the SX900 is on-par with other 120/128GB SandForce drives.

Desktop Iometer - 4KB Random Write (4K Aligned) - 8GB LBA Space

4KB random write performance is no different from other SandForce drives. Only Intel SSD 520 and Corsair Force 3 are noticeably faster, while others fall in the same 215-230MB/s range.

Desktop Iometer - 4KB Random Write (8GB LBA Space QD=32)

Increasing the queue depth to 32 doesn't change the story. While the SX900 is the slowest SandForce drive in this test, it's less than 5% slower than the majority of SF-2281 drives.

Sequential Read/Write Speed

To measure sequential performance I ran a 1 minute long 128KB sequential test over the entire span of the drive at a queue depth of 1. The results reported are in average MB/s over the entire test length.

Desktop Iometer - 128KB Sequential Read (4K Aligned)

Desktop Iometer - 128KB Sequential Write (4K Aligned)

Both sequential read and write speeds are almost the same for all SandForce SF-2200 series SSDs and the SX900 is no exception. This isn't a surprise given that the firmware is essentially the same in all SandForce SSDs, with the exception of the Intel 520 series.

Introduction to ADATA XPG SX900 AS-SSD Incompressible Sequential Performance
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  • leexgx - Friday, June 8, 2012 - link

    use an usa vpn loads of free ones
  • Tujan - Friday, June 8, 2012 - link

    This is yes "nand",. What would be the complexity of simply creating a curcuit board,that fits regular DDR3 ,and places it into the PCI-e slot. Put a battery onto the board,with perhaps a simplified voltage regulator. Then this saves the state of the RAM when the board shuts off. Would be serous situation for such curcuit boards. Ho-hum save the state of the memory,where no change equals,saved state. Strobe etc,. Even the ideal of having RAM on the curcuit board w/o the saving is a serious relationship to performance 'in session' on a computer of course.

    Fail to understand reasons vendors would ask so much for such a PCI-e board. When I see a memory curcuit on a MB for example,a fraction of a whole MB,that would just as well be able to fit onto a removabl PCI-e board. For a PCI slot.
  • jabber - Friday, June 8, 2012 - link

    Gigabyte did this about 7 years ago.

    http://www.anandtech.com/show/1742
  • jabber - Friday, June 8, 2012 - link

    Just not through the PCI-e slot.
  • Einy0 - Friday, June 8, 2012 - link

    Thanks for the trip down memory lane!!! I used to day dream for hours about how I would use one of those.
  • Stahn Aileron - Friday, June 8, 2012 - link

    In one word: Capacity. Next issue would be power efficieny since you would always be feeding it power in some form (be it main power or battery power. And that battery will only last so long.) The power issue is relative minor point though.

    The other main power would be volatility. RAM drives are only useful when you absolutely, positively need high-speed, low latency read/write performance (like forcing cache to DRAM instead of the storage system.) As soon as you power them off, you lose all the data stored on them. Battery back-up systems can only go so far to retain your data. This type of storage is too risky for permanent data storage. Any loss of power to the RAM equates to losing all your data. Unlike non-volatile systems (HDDs, SSDs), you're not recovering that data either.

    You're not gonna see RAM drive tech in the consumer space unless they can makes non-volatile RAM. Right now, it's mainly an enterprise thing. Even then, with the uptake of 64-bit software during the past decade or so in that market, there's very little need for RAM drives since a 64-bit OS will give you direct access to practically any and all RAM you have installed in a system these days. You don't need a RAM Drive workaround to access more RAM (32-bit OSes have and inherent 4GiB memory space limitation without workarounds.) I can only see RAM drives being used in the consumer/professional space if some software used explicitly required cache/scratch space on a drive. Something like Photoshop scratch space would be better served on a RAM drive, perhaps.

    Past that, it's cost. Just the RAM itself is about $10/GB these days (give or take.) Fully assembled SSDs using a common interface (SATA) are averaging between $1 & $2 per GB.
  • Shadowmaster625 - Friday, June 8, 2012 - link

    I have a bricked Sandcrap drive that tells me all that RAISE crap is pretty useless so they may as well just use that NAND for more capacity.

    Hell, they should just advertise it as a 1TB drive. Once it is bricked, who can ever tell the difference?
  • DigitalFreak - Friday, June 8, 2012 - link

    U mad bro?
  • Belard - Monday, June 11, 2012 - link

    Sandforce has become the dominate player in the market. If their controllers were pure crap, then intel wouldn't have touched them. Notice how long intel's G2 drives were THE #1 drives to get, not just in performance but in reliability.

    I admit, I'm a bit confused that intel didn't continue to use their own controller in their top in drive (Their 320 series are like a "G3" and perform slightly better but cheaper than the G2s).

    Also, what sandcrap drive did you get? OCZ makes about 4 different versions of any particular size. Even 6 months ago, you can pick up a 120GB OCZ for $95, but also spend $250... the cheap drive had a much higher failure rate, include DOA. Its performance was crap, becoming slower than a HD after a while.

    Was talking with friends who are looking to upgrade soon. They are going over the various drive brands and pricing. I said, "I don't care... intel 320 or 520. Reliability counts. Saving $50 in exchange for BSOD / performance loss / lack of support isn't worth it".

    I don't know about other brands, but OCZ has no tools for their drives, other than a firmware upgrader. That's it. Intel has a tool-kit, it tells you everything about the SSD, optimization, config, diagnostics and more.

    I'm open to buy a drive from someone else, I'm NOT an intel fan. But I want quality over fandom first.
  • ImSpartacus - Friday, June 8, 2012 - link

    Knowing this was an SSD review, I assumed Anand wrote it. After I read the intro piece, I was CONVINCED that it was Anand. But lo and behold, when I glanced at the top of the next page, I did not see the name I was expected.

    Bravo, Mr. Vättö, bravo.

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