  Predicting neural architecture performance is a challenging task and is
crucial to neural architecture design and search. Existing approaches either
rely on neural performance predictors which are limited to modeling
architectures in a predefined design space involving specific sets of operators
and connection rules, and cannot generalize to unseen architectures, or resort
to zero-cost proxies which are not always accurate. In this paper, we propose
GENNAPE, a Generalized Neural Architecture Performance Estimator, which is
pretrained on open neural architecture benchmarks, and aims to generalize to
completely unseen architectures through combined innovations in network
representation, contrastive pretraining, and fuzzy clustering-based predictor
ensemble. Specifically, GENNAPE represents a given neural network as a
Computation Graph (CG) of atomic operations which can model an arbitrary
architecture. It first learns a graph encoder via Contrastive Learning to
encourage network separation by topological features, and then trains multiple
predictor heads, which are soft-aggregated according to the fuzzy membership of
a neural network. Experiments show that GENNAPE pretrained on NAS-Bench-101 can
achieve superior transferability to 5 different public neural network
benchmarks, including NAS-Bench-201, NAS-Bench-301, MobileNet and ResNet
families under no or minimum fine-tuning. We further introduce 3 challenging
newly labelled neural network benchmarks: HiAML, Inception and Two-Path, which
can concentrate in narrow accuracy ranges. Extensive experiments show that
GENNAPE can correctly discern high-performance architectures in these families.
Finally, when paired with a search algorithm, GENNAPE can find architectures
that improve accuracy while reducing FLOPs on three families.
