efSearch is the search factor at inference time while efConstruction is used when building the index.
I think these are reasonable values.
I’ve started experimenting with these parameters recently. I can tell that efSearch of 128 leads to way better results that the default 16 for retrieval, even though it’s a bit slower. You can experiment with different values of efSearch once your index is built. I’ll share my results soon.
For efConstruction I haven’t tested yet but I’ll let you know.
Feel free to browse the Faiss repo and wiki if you’re interested in tuning the index parameters for your needs.