If we’re agreeing that nothing the OP can do with the stated configuration will get the packets off the CPU, then I don’t see how MT can fix this thread’s symptom with a better software bridge design. The hardware’s PPS rate limitations are fixed at design time, modulo details like the clock rate setting pe1chl brought up.
OP needs to export his config dump for us to review. It's likely misconfig and/or broken L2 fastpath/L3 fastpath (different from offloading to the switch chip).
If instead you’re suggesting that a better software design would somehow offload a configuration like this to the RB5009’s preexisting switch chip and allow it to proceed at line rate, I think you’re overlooking the heterogeneous nature of MT hardware. Unlike the big guys you revere, MT doesn’t get to design custom ICs that support their idealized software designs. The only way to prevent the plumbing from poking up through the porcelain in places when you use this many different COTS chip designs is to nerf all designs to a least-common-denominator level. Under that type of design, the only HW features exposed are those present in all chips used.
Cut the simping for MikroTik. MikroTik relies on merchant silicon (Marvell is their choice) just like Cisco, Juniper and Nokia do for MOST of their products. Let's give a more extreme example, ALL whitebox hardware vendors like Ufi Space or EdgeCore, ALL use merchant silicon.
They all have their own NOS, for example OcNOS in the case of whitebox, and these NOSes decided NOT to use any Linux conceptualisation for the data plane and therefore no Linux-like complexity.
MikroTik code design, UI/UX is so terrible that v7 still doesn't have "long-term" and still they can't offload EVPN/VXLAN/MPLS even though the Marvell ASICs supports it at hardware level.
MT took the opposite path: expose all chip features, requiring the user to know what those are and avoid designs that require RouterOS to activate one of the abstractions you rail against, in order to emulate a missing ASIC feature in software.
MikroTik didn't expose jack. Where's EVPN? The Marvell ASICs on CCR2k supports it, where's the “exposé”?
If you add “custom ASICs” to support that software, then yes, I agree that would result in a cleaner implementation…
Again, NOPE. Cut the simping for MikroTik. ALL vendors rely on Merchant silicon for the MAJORITY of their products, most commonly that's Broadcom.
But you have Marvell, Centec, etc as alternatives, all of which works fine on non-RouterOS NOSes in the market like SONiC or OcNOS.
What can MikroTik do? Cut the shite and allow official ONIE flashing, and let us install our own NOS.