The Synology DS1621+ is a high-end NAS for small business environments rather than enthusiast home users. As the Ryzen CPU doesn't have an embedded GPU, the NAS is lacking proper multimedia capabilities, which is of no concern in a business environment. Storage expansion capabilities are great, allowing for up to 16 drives with two optional Synology DX517 units. These expansion units aren't cheap, but having the option to upgrade the storage capacity considerably if required is great. Moreover, the two NVMe slots are a nice way to boost performance and IOPS. Finally, more RAM out of the box would have been nice, especially as RAM utilization was rather high during the multi-client tests. That said, you can upgrade, installing up to 32 GB, which is more than enough for a Linux box.

The four Gigabit Ethernet ports can be teamed for up to 4 Gbit transfer speeds. This is nice, but I would like to at least see 2.5 Gbit ports. That said, you do have the option to install one of two available 10 Gbit Ethernet cards Synology provides for purchase separately, but such a high-end NAS should come with upgraded Ethernet capability. This is also why it doesn't slot in at the top in my overall performance chart.

At $800, this is an expensive NAS, but let me remind you that you also get the fantastic DiskStation Manager (DSM) operating system, which is among the best, rivaled only by QNAP's Turbo NAS System (QTS). The best thing with DSM is that it looks simpler than QTS, but provides almost the same functionality. In other words, it is more user friendly. On the other hand, QTS provides you with some more options. For example, you can set a custom fan speed instead of selecting operation profiles. Speaking of fans, the DS1621+ comes with two DBB fans, which can endure harsh operating conditions. Double ball-bearings are expensive, but a highly preferred option to sleeve and even rifle bearings, especially under high operating temperatures. The problem is their increased output noise, so they are not ideal for environments where you want to keep output noise as low as possible. Usually, this is not an issue for noisy business environments. Should you want to replace the fans, it is easily done as well. The strong CPU for a NAS offers good performance in both single and multi-client scenarios and doesn't require any active cooling, nor is it power-hungry. Given a NAS is meant to operate around the clock, power consumption is very important. Also don't forget that higher energy consumption results in higher thermals, so you need stronger cooling, which is in turn noisier.

The optional bundle for extending the provided warranty to five years is a welcome option, especially for a business-oriented product like this one. The cost of extending the warranty is around $100. That said, look at the part analysis section and you will see that the DS1621+ uses quality parts to easily outlive its five-year warranty. Delta Electronics also provides the power supply, so it is bulletproof.

In conclusion, this is a good product that doesn't address home users, who will frown upon its high price tag and won't like the limited multimedia capabilities because there is no embedded GPU.