Rejoice, for ridiculously quick PCIe Gen 4 drives are now almost mainstream. Jeremy Laird chooses from six of the speediest NAND SSDs

IT TOOK ITS MERRY TIME. But with the latest 12th Gen Alder Lake CPU family, Intel can finally support PCIe Express Gen 4 on the desktop. Better 18 months later than AMD and its PCIe 4.0-capable Ryzen 3000 CPUs than never, huh?

Whatever. You now have free reign to build a PC based on a platform from either of the core hardware vendors without worrying about interconnect spec. As for why PCIe 4.0 matters, as ever, it comes down to speed. If you want the fastest connection speed for peripherals, you need PCIe Gen 4. And if there’s a single component that benefits most from more PCIe bandwidth, it’s storage.

Gen 4 doubles theoretical bandwidth over Gen 3 to fully 8GB/s in both directions. Thanks to AMD’s early move in the Gen 4 space, there are already a wealth of PCI Express Gen 4 drives to choose from and several get remarkably close to the full capability of the interconnect.

What’s more, SSDs have avoided the debilitating price rises suffered by some PC components over the past year or two. Now, you not only get more speed but also more storage for less money. By CPU and GPU standards, a multi-TB SSD is positively affordable. None of which means, however, that all Gen 4 drives are equal. So, it’s time to find out how six of the very best perform.

Crucial P5 Plus 1TB

JUST NINE DOLLARS. That’s how much extra you currently have to pay for the Crucial P5 Plus 1TB with PCIe Gen 4 capability over the older Crucial P5 Gen 3 drive. The plain old P5, should we need to remind you, returns barely more than half the performance by several measures. Even if you don’t have a Gen 4 capable rig right now, it surely makes sense to go with the Gen 4 drive and future-proof your storage for any possible CPU and motherboard upgrade.

With that in mind, it’s not a huge surprise to find the Crucial P5 Plus is the cheapest drive on test. Less than $130 for 1TB’s worth of Gen 4 goodness in an M.2 package? Sign us up! It’s not as if this drive cuts any obvious corners in terms of specifications either.

Partly, that’s thanks to the fact that Crucial’s parent company Micron is one of the world’s biggest producers of the NAND flash memory that goes into SSDs. So, it gets access to the latest chips for less cash than the competition.

In this case, we’re talking Micron’s latest TLC or triplelevel-cell flash memory and so none of that clunky, cheap QLC gunk. Micron reckons the new 176-layer NAND chips are a major upgrade over the more familiar 96-layer NAND memory, with lower latency, more throughput, and better endurance.

Of course, it’s not just flash memory Crucial does in-house. It has its own SSD controller chips, too, now updated for PCIe 4.0. Crucial hasn’t been forthcoming regarding the specs of the new controller, but we know the old Gen 3 model was a sixcore chip, so that’s likely to be the case again. It certainly has eight memory channels and on this 1TB M.2 drive hooks up to 1GB of DDR4 cache.

Hardware-based AES 256-bit encryption and the obligatory SLC cache mode, which increases performance by allowing a portion of the drive to be dynamically allocated to run in faster single-level-cell mode, are also in the mix. As for write endurance, this 1TB version is rated at 600TB and also covered by a healthy five-year warranty, which should be plenty for all but the most demanding users. In short, there are no obvious omissions, no signs of cutting corners to save costs.

That said, the claimed 6,600MB/s peak read and 5,000MB/s write sequential performance is clearly a little off the pace of the quickest PCIe Gen 4 drives. The same goes for random access performance, which is rated at 630,000 read IOPS and 700,000 write IOPS. Several drives on test this issue are good for one million IOPS, by the official numbers at least. So, something has gone slightly amiss to hit the lower price point.

That carries over to our benchmarks. The P5 Plus proves good for the claimed sequential throughput, though performance in short queue depth 4K random workloads of 69MB/s and 174MB/s for reads and writes is a fair way off the fastest drives. If synthetic benchmarks only tell you so much, the P5 does well in the more real-world PC Mark Storage index, notching up an impressive 3,140 points.

On the subject of sustained performance, throughput drops off consistently after around 300GB of writes, which likely reflects the maximum possible size of the dynamically allocated SLC cache. We also found a brief performance blip after 200GB, possibly due to thermal throttling, the latter arguably confirmed by the fairly toasty peak temp of 69°C under load.