ADATA XPG SX900 256GB SATA 3 SSD Review – Expanded Capacity and SandForce Driven Speed


Our analysis today will be conducted with our Z68 Extreme 7 Test Bench, full description of which can be found here.

In testing, our main objective is to obtain results as pure and as accurate as possible and we want to ensure that no anomalies slip through. Simply put, we want to provide you with the absolute best results the tested hardware can provide. Repetition in testing is standard and, if necessary, we may conduct specific tests in Windows 7 safe mode to ensure the OS has little to no influence on the end result.

In order to validate and confirm our findings, testing is supported by industry accepted benchmark programs. All results are displayed through capture of the actual benchmark for better understanding of the testing process by the reader.

blankWe would like to thank ASRock (Z68 Extreme 7), Intel (Core i7-2600), Crucial (Ballistix), Corsair (H80), Be Quiet (PSU/Fans), and Fractal design (Define XL) for supporting the build of our Z68 Extreme 7 Test Bench.


All SSDs are not created equal and many new SSD enthusiasts realize that when they test their new drive to confirm specifications and ensure all is in order. SandForce controlled SSDs, as in the ADATA XPG SX900 SSD we are testing today, use compression techniques in storage whereas many others do not. This creates a bit of confusion when enthusiasts test the drive with random data through benchmarking programs such as AS SSD and Crystal Diskmark. The results seem to be lower than the listed specifications.

blankThe results actually present a false portrayal of the drives ability when compared to other drives such as Samsung, Crucial or Intel. It is for this reason that all of our comparison testing is done through PCMark Vantage. PCMark Vantage HDD Suite simply provides evaluation results based on transfer speeds reached through typical user patterns. Vantage provides a better testing medium, in that, it sees through the typical synthetic benchmarks and provides us with true to life results of the drive.


The software we will be using for today’s analysis is typical of many of our reviews and consist of ATTO Disk Benchmark, Crystal DiskMark, AS SSD, Anvil Storage Utilities and PCMark Vantage.  We rely on these as they each have a way of supporting one another yet, at the same time, adding a new performance benchmark to the total picture.  Much of the software is free and can be downloaded simply by clicking on the linked title.


ATTO Disk Benchmark is perhaps one of the oldest benchmarks going and is definitely the main staple for manufacturer performance specifications. ATTO uses RAW or compressible data and, for our benchmarks, we use a set length of 256mb and test both the read and write performance of various transfer sizes ranging from 0.5 to 8192kb. Manufacturers prefer this method of testing as it deals with raw (compressible) data rather than random (includes incompressible data) which, although more realistic, results in lower performance results.

blankATTO results of 557MB/s read and 528MB/s write transfer speeds are right in line with the listed specifications and were a bit surprising.  It would be quite an accomplishment to get through testing with a 7% capacity gain and no performance reduction.


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    I don’t think it’s entirely unexpected that ditching RAISE would help increase speeds somewhat. After all, the drive isn’t having to write the necessary parity(?) data anymore to recover from a die failure. With that said, I’ve seen increased write performance from SF’s using the new reference 5.02a FW anyway.

    So it looks like you do get slightly better performance overall and more capacity in exchange for less failure tolerance.

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    It would be interesting to run a pair of these in RAID 0 to see what the low RAISE does to performance.

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    Can’t see how there would be any major surprises, Crucial have been using the 0% over-provisioning for years, The only over-provisioning they’ve had has been the difference between the size of actual memory modules ( gigabytes ) and the actual size of the ssd drive ( Gibibytes ) it still leaves 7% difference for over-provisioning, which is classed as 0%.

    More over-provisioning still makes for a better ssd drive where it matters, but I guess size is everything as far as the market is concerned.


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    This is a great review you have there as usual 🙂

    I am Muhammad Al-Jawhary, an Arab reviewer and technical editor, and I have a 128GB sample of the drive that I have reviewed here:

    That makes us two sides of the same coin, you have done the only review in English (as far as I know), and I have done the first and only review in Arabic, too 😀

    The performance is great, and it has 8 GB more than its brother; the S511.

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      Ummm isnt that my photo of ‘all the ssds’ in your review? I would appreciate the link back to our site and article if you are using any of our literature or piks.

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        Thanks for your reply, it is a great pleasure to be here 🙂

        Actually, it is your pic, and the pic has a hyperlink embedded (If you press the image, you will be directed to the great article).

        We may have some future cooperation together, I may be able to translate some of your guides and articles and post them in the Arab world, and of course, the credit is all yours, not mine.

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        When I click on the pik, it brings me only to the pik…. Can we fix the link so it goes to the article? And yes, I am sure we can affiliate post for one another in the future.

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        Actually, the image has a hyperlink as I said before, but the site uses a script to show the images, which in turn hides the hyperlink. Nonetheless, I have added a credit line under the photo that contains the link. Sorry for the inconvenience 🙂

        Have you seen those numbers I got with the drive? They used asynchronous NAND flashes with the 128GB version! The same NANDs used with Kingston’s SSDNow V+200.

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    There is a slight inaccuracy in your reviews which is (implicitly) already mentioned above, but which i’d like to clear up. Flash memory has raw capacities of binary powers, this one e. g. has a raw capacity of 256 * 2^30 = 274877906944 bytes = 256 “GiBi” Bytes. Vendors prefer to use decimal powers, as the numbers are slightly higher, so this SSD has a raw capacity of 275 * 10^9 Bytes = 275 GB. 7% of these are used for over-provisioning leaving the user with 256 GB = 238 GiB. Windows, again, uses binary powers to display drive capacities, so the latter number is what you see there. (No, NTFS formatting doesn’t swallow 18 GB of the drive capacity. 😉 Other Sandforce SSDs with 240 GB = 223 GiB user capacity use 14% of the raw flash capacity for over-provisioning.

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