Automatic interface affinity (sim affinity -a) is the default. With 2 10gig interfaces a starting split of 6/24 is quite reasonable; if there is a large amount of fully-accelerated traffic you might need more SNDs than that.
If there will only be two main interfaces used and they will handle almost all the traffic, Multi-Queue might be prudent as well depending on network traffic load and the burstiness level of network traffic.
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Second Edition of my "Max Power" Firewall Book
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