Xiaomi Router HW questsion

Hello , i am currently working with Xiaomi Mini which is a great device running OpenWRT.
But recently i have been taking it a bit to the limit. i have an external HDD, Aria2, rtorrent and other tools and i think i am seeing that the CPU is almost full and i wonder if doing the upgrade to the Xiaomi R3P Pro which has dual core and more Mhz.

Any tips or recommendations are welcome i just want to make sure it way more powerful to run more tools like tcpdump and vpns without sacrificing its performance.

I am going Xiaomi cuz of the price ranges, if you want to recommend another router i just need it to have USB for external HDD.

Thanks in advance for your comments