The Crucial P5 Plus is the natural evolution of the PCI-Express 3.0-based Crucial P5. With PCI-Express 4.0 considered "standard" for pretty much any new build nowadays, it makes sense to offer a product that supports this new speed grade. We saw good results from the in-house custom-design controller on the P5, and the P5 Plus doesn't disappoint, either. It is based on an all-new eight-channel DM02A1 controller, which to the best of our knowledge is an in-house development by Micron, Crucial's parent company. As expected, the TLC NAND flash chips come from Micron, too. These are the brand-new B47R 176-layer chips we've first encountered in our Phison E18 + B47R review. Last but not least, a DRAM cache is also included for the mapping tables of the SSD, which helps with random writes.

What's important here is to highlight that all components on the SSD are produced by Micron, which certainly helps with manufacturing cost, but sourcing everything in-house also means you're not as dependent on component shortages as other vendors who are at the mercy of the free market—a huge advantage, especially today. Besides Crucial/Micron, only Samsung and Hynix have the ability to build a solid-state-drive using exclusively their own components.

Synthetic performance numbers of the Crucial P5 Plus are lower than what I would have expected given the drive's positioning. Especially random IO, both read and write, at low queue depths is lower than most competing drives. Sequentials reach around 4 GB/s in our mix of QD1 to QD4, which focuses on typical client workloads that never run at high queue depths. This puts the P5 Plus roughly in the middle, between the best Gen 3 SSDs and Gen 4 high-end drives. Once we go to higher queue depths, results do reach impressive 400K IOPS and 5 GB/s.

Our real-life test suite goes beyond synthetic benchmarks and runs the actual applications at 80% disk full, which is a much more realistic scenario and not as easy to optimize for as synthetic workloads on an empty drive. Performance results for the Crucial P5 Plus are good, matching the ADATA XPG Gammix S70, which uses the Innogrit IG5236 PCI-Express 4.0 controller, and it beats the Phison E16 Gen 4 controller on the Gigabyte AORUS SSD. The fastest drives in our test group are a few percent faster: Corsair MP600 Pro +3%, Samsung 980 Pro +4%, and WD Black SN850 +5%. These are small differences, barely noticeable unless you use a stop watch. Compared to PCI-Express 3.0 drives, the Crucial P5 Plus offers a 10% performance uplift over value Gen 3 drives, and the best PCIe 3.0 SSDs are close behind, almost equally as fast. The aging SATA 2.5" SSDs are around 20% slower, SATA QLC even 40–50%.

With a pseudo-SLC cache size of 94 GB, Crucial's engineers picked a reasonable mid-sized capacity for the cache that soaks up incoming bursts of write activity, which is comparable to many competing SSDs. Filling the drive completes at around 1.3 GB/s, which is a good result, definitely faster than most Gen 3 SSDs, but slightly behind what the WD Black SN850 (1.6 GB/s) and Samsung 980 Pro (1.9 GB/s) offer. Of course, momentarily stopping the write activity will have the SLC cache free up capacity immediately, so full write rates are available as soon as you give the drive a moment to settle down.

Unlike some other M.2 NVMe SSDs, the Crucial P5 Plus doesn't come with a heatsink preinstalled, and it doesn't need one, either. In our thermal stress test, we saw no thermal throttling. This is VERY impressive, especially considering this is a PCIe 4.0 drive with 4 GB/s write rates. It seems the Micron SSD controller is an extremely energy efficient design—more efficient than all other controllers on the market except for the Samsung PCIe 4.0 Elpis, which seems to be of similar efficiency. What is noteworthy, however, is that the drive's own temperature reporting is very optimistic, as it claimed a temperature of 73°C when the actual temperature was 91°C. Not a big deal, just something you should be aware of.

This low heat output makes the Crucial P5 Plus one of the best candidates to upgrade the internal memory of your PlayStation 5. While Sony's guidelines require a heatsink to be installed on SSDs, our results show that this isn't needed, unlike other drives that would overheat in the confined zero-airflow location of the PS5.

The Crucial P5 Plus is readily available at a price of around $180 for the tested 1 TB version. This is comparable to other PCIe 4.0 flagship SSDs, like the WD Black SN850 ($180), Samsung 980 Pro ($190), and Corsair MP600 Pro ($170). I still feel that the Crucial P5 Plus is a bit expensive considering the performance it offers. Right now, there's several alternatives on the market that offer higher performance at lower pricing than the P5 Plus, including the WD Black SN850 and Samsung 980 Pro. I feel that as soon as Crucial brings down their price a little bit, closer to the $150 mark, the P5 Plus could be an excellent alternative for people who want a modern high-speed SSD that offers good performance, yet isn't as overpriced as many other Gen 4 SSDs. If you are willing to consider drives with PCIe 3.0, too, quite some savings are possible with only small performance losses. Drives that should be on your short list are the ADATA SX8200 Pro for $100, HP EX950 for $130, Samsung 980 for $120, and Kingston KC2500 for $120.