The PCI Express Gen 4 interface is rapidly approaching default status, especially if we are talking about new hardware rather than installed hardware. Intel's latest desktop and mobile CPUs support PCIe 4.0, AMD jumped on the PCIe 4.0 wagon in 2019, the Xbox Series X/S and Playstation 5 also support the standard, and the newest Intel and AMD products are also supporting PCIe 4.0.

As for solid state drives, the early adopter phase is well underway with many high-end PCIe 4.0 drives available and a few value drives. The new ADATA XPG Gammix S50 Lite (2TB configuration, M.2 2280 format) we tested falls into the latter category. However, whereas some Gen 4 drives achieve their low prices by using inexpensive and not necessarily cheerful QLC or quad-level flash memory, ADATA uses TLC or triple-level flash memory, in this case 96-layer Micron chips This allows for a bargain price.

Not that I want to instruct anyone on the fine art of orally applying a vacuum to an egg, but adding cell level and thus data density to NAND flash memory reduces performance and endurance; QLC is slower and does not last as long as TLC before it wears out. Much of this can be masked with tricks such as running parts of the drive in pseudo-SLC mode to improve performance, as the Gammix S50 Lite actually does. However, the underlying performance of the flash memory used will eventually catch up. More on that later. [The answer, at least in part, is a more affordable PCIe Gen 4 controller chip. The original Gammix S50 was a high-end PCIe Gen 4 drive with a Phison controller. This "Lite" model is less expensive and features the new Silicon Motion SM2267 controller.

The SM2267 is a lower-cost option in SM's latest PCIe 4.0 controller portfolio, with the less expensive 28nm where more expensive controllers are typically manufactured at or near the 12nm manufacturing node, whereas more expensive controllers are typically manufactured at or near 12nm. They are also limited to four memory channels and two ARM Cortex R5 CPU cores. For example, the SM2267's SM siblings are 12nm, with eight memory channels and four Cortex R8 cores.

Nevertheless, this new budget PCIe 4.0 controller is faster than SM's previous generation of high-end PCIe 3.0 controllers, the SM2263, with a peak performance of 1,200 MT/s versus 800 MT/s of the older chip. In addition, the high density of the flash chip allows for large capacities (in this case, a full 2 TB) with only four channels. Another area where corners can be cut is RAM allocation: the ADATA XPG Gammix S50 Lite has 1GB of DDR4 cache, and 2GB is expected for a drive with 2TB capacity. Still, a little less DRAM is much better than no DRAM at all.

Incidentally, the officially announced performance lists sequential throughput at 3,900 MB/sec read and 3,200 MB/sec write, and 4K random access at 490K read IOPS and 540K write IOPS. Overall, the philosophy behind this product is quite simple: ADATA aims to deliver the equivalent of premium 8-channel PCIe Gen 3 performance, such as the previous generation WD Black SN750 and Kioxia Exceria Plus, in a low-cost quad-channel PCIe Gen 4 drive The goal is to deliver the equivalent of premium 8-channel PCIe Gen 3 performance, such as the WD Black SN750 and Kioxia Exceria Plus, in a low-cost quad-channel PCIe Gen 4 drive.

Rounding out the speeds, feeds, and specs is 1,480TB of write endurance, enough for all but the very few ultra-intensive users, and a healthy 5-year warranty. Physically, this 80mm M.2 drive has a low-profile flat heatspreader that is claimed to reduce temperatures by up to 20%. Overall, it costs about three-quarters of the cost of a high-end PCIe Gen 4 drive with a more expensive 8-channel controller. In other words, it is a very attractive proposition on paper.

But what about performance? Peak performance in CrystalDiskMark 7, the most forgiving benchmark, was 3.9 GB/sec read and 3.2 GB/sec write, in line with the claimed performance. The ATTO and AS SSD metrics are a bit lower, but in any case, these numbers are very competitive with high-end PCIe 3.0 drives.

We compared this drive to the Samsung 980 1TB ($110), the Silicon Power US70 2TB ($350), and the fastest SSD, the WD_Black SN850 1TB ($200). This covers other budget products as well as pure speed alternatives.

As for 4K random access, it still depends somewhat on the application used. However, as a rough conclusion, the ADATA XPG Gammix S50 Lite 2TB returns 71 MB/sec read and low to mid 200 MB/sec write, which is slightly above expectations, if not remarkable.

Temperature management was very good, peaking at only 53°C during testing. Well-managed temperatures suggest that the initial 1.1 GB/sec internal file copy speed, which fluctuated between 300 MB/sec and 500 MB/sec after approximately 350 GB of data storage, was due to SLC cache depletion rather than thermal throttling. However, this is inconclusive, since speeds between 3,300 MB/sec and 500 MB/sec are rather lower than what would normally be expected for TLC flash.

Overall, the ADATA Gammix S50 Lite 2TB largely meets the first suggestion. It performs nearly as well as a high-end PCIe 3.0 drive. Its low peak operating temperatures are also impressive, but given its obvious weakness in terms of sustained performance, we have to call it academic. Still, if you're looking for a 2TB SSD with a decent 5-year warranty and no performance issues, this product is a worthy candidate. Otherwise, check out our guide to the best SSDs for gaming.