Well known technology
As we've said before, the TP-Link Touch P5 is a AC1900 model, not the newest of the newest. The Archer C9 we saw early this year was in the same boat. If we look back even further and also to other brands, we find that two years ago we had already reviewed the RT-AC68U from Asus and the Linksys EA6900, both also offering bandwidth speeds up to 600 Mbps at 2.4 GHz and 1300 Mbps at 5 GHz.
If we identify a router with AC1900, you can bet on it that it's a Broadcom-based model. TurboQAM, which can reach speeds of up to 600 Mbps at 2.4 GHZ and is also a part of the AC1900-routers, is a technology developed by Broadcom. It's not very useful though, since almost no clients support it. We have yet to encounter a laptop or smartphone with support for this technology. If you want to make use of it, you'll need a device like the PCE-AC68, a PCIe adapter from Asus.
It doesn't come as a surprise we found also found Broadcom chips inside the Touch P5. The well known BCM4709 has been chosen as the CPU, it's a dual-core Cortex A9 chip, with cores clocked up to 1 GHz. It has been inside most, if not all Broadcom-based high-end 802.11ac-routers since the Netgear R7000 Nighthawk. The wireless connections are maintained on both frequencies by a BCM4360. Lastly we find 256MB of memory next to the CPU.
It's clear that the technology isn't very new, but we wouldn't call it dated. This is because the router market has made a typical turn in recent years. Flagships weren't really replaced, they simply added newer ones, while the former flagships simply remained on the market, at times even without dropping the price. This caused products like the RT-AC68U to remain relevent, even though they aren't flagship models anymore.