Adata XPG SX900 And Premiere Pro SP900
Adata's first SSDs equipped with second-gen SandForce controllers belonged to the S511 family. They were armed with synchronous ONFi-compatible NAND and configured for 7% over-provisioning.
A few months back, however, SandForce started giving its partners a way to disable over-provisioning altogether, thereby increasing user-accessible space. If a drive included 256 GB of capacity, the controller company basically made it possible for vendors to give their customers access to all of that space.
Adata is one of the companies to take SandForce up on its offer, creating the SX910, SX900, and SP900 SSDs. As we see so often, differentiation happens through varied NAND interfaces and technologies. The SP900 is Adata's budget-oriented model, featuring 25 nm asynchronous NAND. The SX900 and SX910 enjoy faster 25 nm synchronous memory.
The SX900 and SP900 both come with a standard three-year warranty. The SX910 is identical to the SX900, but it carries a five-year warranty. You probably won't see much of the SX910 in the U.S., however, due to its higher price tag.
In 4 KB random reads, 4 KB random writes, and 128 KB sequential reads, the performance we see from Adata's SX900 and SP900 drives is nearly identical. Strange, right? We know from our testing that, at 120/128 GB, there is a measurable difference. But at 240/256 GB, there is enough NAND on this drive to saturate every channel, despite the SP900's slower memory interface (which really isn't all that slow to begin with).
We see the largest gap between drives in our 128 KB sequential write test. When they're operating on compressible data, both SSDs achieve great performance. Limiting the workload to incompressible data changes this, though, and the SX900 is about 60 MB/s faster from a queue depth of two, onward.
