A 256x3=768-byte lookup table will almost certainly be faster on a CPU. It will fit easily in L1 cache, and can extract 3 bytes at a time.

Ironically, x86 has an instruction, XLATB, that does almost exactly this (looking up a byte in a 256-byte table) -- but using it is actually slower than using an equivalent MOVZX RAX,AL; MOV AL,[RBX+RAX] sequence on modern CPUs.

I was wondering the same thing.

Obviously, it partly depends on the implementation machine, how big a hole the tables blow in your cache, how fast the multiplies are, etc.

But it probably also hugely depends on the format that you want your trits in. If you use them unpacked, e.g. one trit per byte, then even if you're using tables, you still have to do a lot of manipulation (e.g. either shifting and oring, or having different tables, and a table lookup per trit and adding together to get the binary).