AS SSD is a benchmark that uses non-compressible and completely random data. What this means is that the drives using the SandForce SF-2281 controller cannot compress the data first, which takes away one of the strong advantages of this controller. Therefore this is a useful benchmark because drives that use the SF-2281 controller don't gain an upper hand.
AS SSD is a benchmark that generally favors Marvell-driven drives and the SanDisk Ultra Plus performed respectably as it proved itself to be more than a match for its more illustrious Extreme counterpart. Sequential read and write performance was very strong and it was capable of keeping pace with the high-end drives such as the OCZ Vertex 4 and Intel SSD 520 Series. Interestingly, the SanDisk Ultra Plus was quicker than the Plextor M2S, despite having what is essentially a scaled down version of the same controller in the Plextor drive.