The Samsung 990 Pro has been on the market for a while, but was fairly expensive in the past, which made it uninteresting and I felt it wasn't worth spending my own money on, just to write a review. Samsung's SSD division is ignoring us for some reason so there is currently no way to get a sample, not even a loaner (probably some political BS, because I'm in Germany and the site is in English). Recently they've brought the price down a lot, from a crazy $250 MSRP to more reasonable $150 for the tested 2 TB version. I found a great deal on a sealed second hand drive, for the equivalent of USD 110, so here we are.

The Samsung 990 Pro is a PCI-Express 4.0 SSD, just like the Samsung 980 Pro. However, the 990 Pro does come with a newer controller and more modern NAND flash. Just like the 980 Pro, the 990 Pro is TLC—the epic Samsung 970 Pro was MLC. Not much is known about the new "Pascal" controller, only that it's made on an 8 nanometer process at Samsung and comes with various optimizations and improved caching logic. There's also some improvements to energy efficiency, more on that later. The NAND flash is now Samsung 176-Layer V-NAND v7, and 2 GB of DRAM cache is included, too.

Synthetic performance results of the Samsung 990 Pro are impressive, the drive claims top spots in the rankings, showing considerably better performance than the Samsung 980 Pro. Just like Phison, Samsung is good at optimizing their drives for synthetic reviewer workloads, which are running on an empty drive. That's why it's important to also include real-life testing. We're even running those tests with the drives filled to 80% capacity, not empty. This approach puts additional strain on the various algorithms and the SLC cache, just like in real-life.

In real-life the Samsung 990 Pro does extremely well, too, and comes out as the fastest PCI-Express 4.0 SSD that we've ever tested. It is able to beat the Phison E18+176L combo by a tiny 1%, just like the Hynix P44 Pro and the WD Black SN770/850. Compared to the Samsung 980 Pro, the performance uplift is 4%—more than I expected. A few percent don't mean much for actual real-life usage though. All of the top spot SSDs will give you an excellent experience and the subjective differences will be hard to tell. While PCI-Express 5.0 doubles the theoretical transfer rates, random IO hasn't improved much, which means actual real-life performance will be virtually unchanged, unless you do a lot of sequential transfers all the time.

The SLC cache of the 990 Pro is "alright" with 187 GB on the 2 TB drive, but other competing models do come with much bigger caches, which helps them soak up bigger bursts of write activity. The size on the Samsung 990 Pro is still plenty for nearly all scenarios, so this is not a major issue. Filling the 2 TB capacity completed at an average of 1.8 GB/s, which is good—similar to the 980 Pro and other high-end drives. However, the best Phison E18+B47R drives, or Netac's NV7000-T do much better here, reaching around 2.5 GB/s.

Our power consumption testing shows that there's only minor improvements to power consumption, the drive's power profile is similar to the 980 Pro. The only noteworthy difference is that energy efficiency (MB/s per watt) during writes is improved considerably—I suspect due to the new flash, and not the controller. On an SSD, all power is converted into heat—keeping it busy will increase the drive's temperature.

The Samsung 990 Pro handles the heat very well though, even without a heatsink. In our worst-case thermal stress test we were able to get the drive to throttle, but only briefly, and only when hammering it with hundreds of GBs of writes at multiple GB/s. The thermal throttling algorithm is also well-behaved, you still get 1.3 GB/s when throttled. Samsung does offer a variant with heatsink for $15 more, I see no reason to spend that money. For the typical day-to-day usage tasks the thermal performance is easily good enough, no need to worry.

Newegg has the Samsung 990 Pro 2 TB for $150 right now, on Amazon it costs $190. Even $150 is not cheap, considering that you can get the WD Black SN850X for $120, the SN770 is even just $100. Strong competition also comes from the various Phison E18 drives, which you can find at pretty interesting price points, too: $80 (Silicon Power XS70) and $100 (Addlink S95). We also recently reviewed the Netac NV7000-T, which achieves excellent performance and is available with free shipping from China for just $80. On the other hand, Samsung is a huge brand, with an outstanding reputation and top-notch support network. Do make sure you upgrade the SSD to the latest firmware if you plan on using a 990 Pro, older versions had some issues.