Yes, there is a hardware acceleration in the original firmware. The DSL driver is also not identical. (The available open-source drivers don't contain a working data path. And the current implementation in OpenWrt is not very efficient because it copies every packet. Unfortunately, I couldn't find a better way that works.)
Performance as a pure modem is fine, you'll be able to use the full data rate.
Hardware acceleration not so much, ipq40xx is both missing the 'old' hardware NAT and NSS cores, but the vendor software does use its own replacement for software flow-offloading (SFE).
If the full DSL speed can only be used in modem mode, there is no real incentive to use Openwrt right now, right?
I would love to use it, but if stock is more efficient I think I will use it
Well, under OpenWrt you can configure the 7520730 as true bridged modem, under FritzOS that is not an option...
It depends, if stock allows all things you want your router to do then that seems like a viable way forward for you.
Are you sure about that? Qualcomm's product brief mentions a "Hardware NAT engine". And the section about packet acceleration in support data from AVM's firmware also suggests that it is available:
/proc/net/avm_pa/status:
State : enabled
HW State : enable
may I ask how you went forward? in two weeks my DSL line will be upgraded to 250/40 and Im using 7520 myself, too. So Im curious how everything worked out for you
I did a small number of additional test combinations, but was barely able to reach 200Mbits in any combination. (e.g. SW Flow + packet steering all CPU + IRQ Balance)
So for now I will not use the device (since I have another 7590 AX), but will keep it.
In the near future I want to upgrade to an Wifi 7+6E Router, maybe BPI R4.
In this case I need a seperate VDSL Modem, where I can use this box. Most likely with FritzOS set to false credentials, allowing other devices to create their own pppoe connection and Wifi disabled.
Power consumption under Openwrt is around 5.5-6.0W and 6.0-6.5" with FritzOS8.
interesthing, so I keep my expectation low.
I have a Telekom Smart 3 router, I kept it in reserve as it can be switched to full modem mode, including passthrough of vlan 7. They are cheap second hand. In case you need a modem option, you can find them on Kleinanzeigen etc.