When we test most computer hardware we typically use a blend of "real world" and synthetic tests, but that can be difficult to pull off with something as unpredictable as wireless networking. There aren't any established benchmarks per say and it is impossible to remove variables in testing environments anywhere outside a laboratory, so as always your mileage may vary. Here in the real world where we test, performance varies according to a variety of factors, including where the router is placed, the size and construction of your dwelling, interference from neighbors, and more. However, we do our best to illustrate both real world and "best case scenarios" with our testing, and for that we relied on the program NetPerf. This tool allows us to setup one PC as a server, and one as a client, and test the connection speed between the two computers.
The wireless adapter we used for these tests was a Broadcom BCM4360 which is the onboard NIC inside a Macbook Pro we used for testing (running Windows 10 via Boot Camp). We tested at both 20 feet away with line-of-sight, and 30 feet away with two walls separating the computers. We tested both TCP and UDP packets; TCP represents the "real world" expectation and UDP represents the best case scenario. To make things actually "real world" we also connected a USB 3.0 hard drive to the routers and tested a file-copy at 20 feet from the router on both 2.4GHz and 5GHz channels. Both of the PCs we used for testing were running Windows 10, and we ran each bandwidth test three times and recorded the average of the three runs. We think these tests provide a fair representation of what one can expect in many environments using these routers at medium range.
In our test at 30" on the 5GHz band we see the Synology Router can hold its own against far more expensive routers, though to be fair to those routers they are mostly tri-band routers. Its transmission speeds were excellent in both measures and overall it was right up there with the fastest routers we've tested.
At 20 feet with line of site using the 5GHz band, the Synology Router was the fastest model we've tested thus far. Its transfer speeds were better than the next-fastest router by almost 100Mb/s, which is not small feat. Overall its safe to say the Synology router smoked the competition at close range.
In our 2GB file transfer test at 20 feet, the Synology Router placed respectably in the middle of the pack.
Using the slower 2.4GHz band, the Synology Router shows its first sign of weakness, as it was surprisingly a lot slower than the competition. We had to run this test many times just to get it to complete, as often times it would simply error-out. Perhaps a firmware update will remedy this for Synology in the future. The system's hardware is certainly more than capable.
Once we moved the client closer to the router, and removed any obstructions, it performed much better on the 2.4GHz band, but again, not as well as its competition has done previously.
Given its up/down record at 5GHz and 2.4GHz bands, we weren't sure what to expect from the Synology RT1900ac, however, it beat all the other routers in its file-transfer tests. Perhaps this is Synology's NAS background coming into play, as it was able to move the files off our external hard drive faster than any other router we've tested previously. Nice; really nice actually