Objective. Test GELU vs. FAct on the TabMini/PMLBmini suite of real-world tabular datasets with N≤500 rows, where deep nets are usually a bad idea in the first place, and see if either activation has an edge.
| GPU(s) | not recorded (tabular MLPs, N≤500 rows — seconds per run) |
| Dataset(s) | TabMini / PMLBmini (15 real-world N≤500 tabular datasets) |
| Model | MLP (width-16 config), logistic-regression baseline included |

Result summary
- Across the 15-dataset suite, mean AUC is noise-level tied between GELU and FAct — no overall winner.
- On mux6 (a 6-input multiplexer Boolean function, 128 rows): FAct K=2 test AUC 0.977 vs. GELU 0.941 vs. logistic regression 0.719.
- On parity5 (5-bit parity, 32 rows — the hardest possible case for a linear model): FAct K=3 0.664, FAct K=2 0.627, vs. GELU 0.467, vs. logreg 0.200.
- Both are exactly the two datasets where logistic regression fails hardest — FAct’s edge shows up precisely where the underlying function is least linearly separable.
Insights
- FAct’s advantage on tabular data isn’t a blanket “deep learning beats logreg” story — it’s concentrated on the two datasets whose ground-truth function is a genuine Boolean XOR-like structure, i.e. it’s dataset-structure-dependent, not a simple extension of the MNIST/CIFAR image results.