With a new generation of PCI Express 5.0 drives coming out, perhaps as early as next year, the latest SSDs based on the PCIe 4.0 protocol are beginning to hit the limits of PCI Express 5.0, the fastest consumer storage interface yet at this time. They are starting to run into the limitations of PCI Express 5.0, which is still the fastest storage interface for consumers at this time.

Here we see the new PNY XLR8 CS3140 in a 1TB configuration; PNY claims sequential reads on this Gen 4 drive are over 7,500 MB/sec. Given that this is a quad-lane SSD, the theoretical maximum bandwidth is 8GB/s. Assuming at least some protocol overhead, we are looking at SSDs that are as good as or better than what is available today in terms of peak read speeds.

Incidentally, the powerful Samsung 980 Pro and Sabrent Rocket 4 Plus both have top speeds of 7,000 MB/s or 7 GB/s. The XLR8 is also slightly faster than the lightning-fast Adata XPG Gammix S70, which is claimed at 7,400 MB/s. As for writes, the peak sequential performance of this 1TB model is less spectacular at 5,650MB/sec, but the more powerful 2TB drive is clocked at 6,850MB/sec, which is quite close to the PCIe Gen 4x4 limit in both directions at this point.

For whatever reason, PNY is pretty tight-lipped about random access and IOPS performance. As for other details, such as controller chipsets and write endurance, PNY is never willing to share. However, a peek under the hood reveals that the PNY XLR8 CS3140 is powered by a Phison PS5018-E18 controller and four 256GB packages of Micron 96-Layer 3D TLC NAND. [The E18 is an 8-channel NVMe 1.4 chip manufactured on TSMC's 12nm process. It has a total of five CPU cores, three based on the general-purpose ARM Cortex R5 IP and two of Phison's own design; according to Phison, the E18 has a read speed of 7.4GB/s and write speed of 7GB/s, plus no less than 1 million IOPS.

Elsewhere, this 1TB drive has 1GB of DDR4 cache memory and a fat, large heat sink for thermal protection. In any case, in our tests, the XLR8 was, perhaps not surprisingly, quite close to a Sabrent drive of similar specifications in terms of peak throughput. That is, reads are closer to 7 GB/s than the claimed 7.5 GB/s and lower, depending on the benchmark software used; the XLR8's sequential write speed is likewise slightly off the claimed figure.

As for 4K IOPS performance, the overarching narrative is that the drive delivers excellent numbers, but does not reach the absolute limits that NAND flash-based SSDs can currently achieve. For this reason, we would like to see WD's Black SN850, although the difference is not huge. Of course, the only real big step up in IOPS performance is Intel's Optane drive and its exotic 3D Xpoint memory. But that is a whole other can of worms powered by phase change.

At any rate, in terms of sustained performance, the XLR8 maintained an initial internal file copy performance of 1.7GB/sec over 300GB in a proper drive preparation procedure prior to benchmarking, then dropped to a fluctuating range of roughly 400MB/sec and 800MB/sec. The performance dropped to a range of approximately 400 MB/sec and 800 MB/sec.

Thanks to the powerful heat sinks, the controller chip cooled even under sustained load, with a maximum temperature of only 36 degrees Celsius. This suggests that the 300GB performance cliff is a limitation of the SLC cache, not thermal throttling. In any case, that is a pretty big chunk of bandwidth to play with before performance begins to suffer.

Overall, the PNY XLR8 CS3140 is a solid enough all-around performer; it is based on the proven technology of the Phison controller chipset and Micron NAND memory and comes with a 5-year warranty. Therefore, the lack of full disclosure on write endurance is not a major concern.

That said, the PNY XLR8 CS3140's peak performance falls far short of its official claims. It was also a bit slower than the best in PCMark 10, Final Fantasy XIV, and real-world file transfers. For these reasons, the XLR8 will live or die according to its comparative value proposition.

There is a heatsink-less version available for about the same price as the Sabrent Rocket 4 Plus, but I would be willing to pay an extra $10 or so to get this rugged, nicely cooled model. At least I would be if it weren't for the fact that the WD Black SN850 is also available for about the same price; WD's drives are classy all-around performers and would be hard to pass up.