ASSSD is a benchmark that uses non-compressible and completely random data. What this means is that the drives using the SF-2281 controller cannot compress the data first. This is good to test drives like the Intel SSD 520, Kingston HyperX, OCZ Vertex 3 and other such drives against SSDs that don't use the SF-2281 controller to gain an upper hand.
When it came to sequential read and write tests, as well as read and write of small data of 4K file size, there was very little to separate the new Intel SSD 520 series from the current crop of SSDs. The new Intel SSD posted very good results and its performance in this aspect is generally solid. This was true for the copy test as well, which is a simple test which measures just how fast the drive could copy a variety of files and folders.
However, coming to the most important test of 4K read/writes speeds with 64 threads, which best simulates everyday practical use with a lot of data being queued, the Intel SSD 520 series pulled ahead quite clearly - posting a 4% and 8% lead over the second fastest drives in both read and write operations. On this test, it was also more than twice as fast as the previous generation Intel SSD 510 series. The new drive couldn't have come at a better time as the SSD 510 series was looking long in the tooth even a few months back.