The ADATA XPG SX950 480GB SSD Review: In Search of Premium

AnandTech Storage Bench - Heavy

Our Heavy storage benchmark is proportionally more write-heavy than The Destroyer, but much shorter overall. The total writes in the Heavy test aren't enough to fill the drive, so performance never drops down to steady state. This test is far more representative of a power user's day to day usage, and is heavily influenced by the drive's peak performance. The Heavy workload test details can be found here. This test is run twice, once on a freshly erased drive and once after filling the drive with sequential writes.

When the Heavy test is run on a fresh drive, the ADATA XPG SX950 delivers a good average data rate that is a bit higher than the Crucial BX300 and close to the level of Samsung's SATA SSDs. But when the drive is full, the SX950 suffers greatly in the manner of the SU800 and the Crucial MX300, while the BX300 is minimally affected.

Both the average and 99th percentile latencies highlight how poorly the SX950 performs when the Heavy test is run on a full drive, but the latency when the test is run on a fresh drive is normal.

The average read and write latencies of the SX950 are both significantly higher when the Heavy test is run on a full drive, but the write latency is again far more strongly affected. For both reads and writes, the full-drive performance is better than the TLC-based ADATA SU800, but nowhere close to the standard set by the Crucial BX300.

The MLC-based SSDs almost all show very little degradation in 99th percentile read and write latencies when the drive is full. The exceptions are the ADATA SX950 and the DRAMless OCZ VX500. The 99th percentile read latency of the SX950 is higher when the drive is full, but still better than the planar TLC drives. The 99th percentile write latency on the other hand grows by more than an order of magnitude to almost 95ms.

The ADATA SX950 scores very well on energy usage when the Heavy test is run on an empty drive: it matches the DRAMless OCZ VX500 and comes close to the Crucial MX300, which uses a Marvell controller fabbed on a newer and lower-power process. The Crucial BX300 uses 14% more energy largely due to taking longer overall to complete the test. The situation is reversed when running the test on a full drive: the ADATA SX950 takes much longer to complete the test and is doing a lot of costly background garbage collection, though it still at least beats the planar TLC SSDs and ADATA's own TLC-based SU800.