Adata recently introduced a new series of high-end SSDs. The SPX SX910 SSDs are built around the same SandForce SF-2281 controller that we've seen in many SSDs in recent years. Adata claims to have equipped the SX910 with "carefully selected flash chips of the highest quality," and includes five years of warranty. The SSDs come with a 3.5-inch installation bracket and Acronis migration software.
Adata promises read speeds of up to 550 MB/s and write speeds up to 530 MB/s. The model we received for testing comes with SandForce firmware version 5.0.2. Adata disabled SandForce's RAISE feature (just like on the SX900 SSDs) in order to make the full 256 GB available instead of the 240 GB that is otherwise typical for SandForce-based SSDs. RAISE uses one flash chip for storing parity data for the other chips, so that one chip can malfunction without all data being lost. You no longer have this safety precaution with Adata, but it's so rare that a single flash chip breaks while the rest of the SSD is still functioning properly. SSDs with different controllers don't even have the option for this feature.
The SX910 256GB has 16 Intel 25nm flash chips. The current price for the SSD is about £190, which makes the per-gigabyte price about £0.74. There are of course more affordable SSDs out there, but for product with five years of warranty and the included package this is not bad.