runtime comparison between inferring vs. instantiating memory functions?

Doubtful. Many years ago it was slower, where synthesis would break it all down to logic and build it back up to memories, but I'm pretty sure there's kind of an "auto-detect" of the memory and it synthesizes them very fast. 10 hours seems wrong though. How long is it for:

1) Synthesis?

2) Fit?

2a) Routing - A message appears in the .fit.rpt saying how long this took.

2b) Placement - Again, a message

2c) Physical synthesis if you have this on - More messages for both an early and late physical synthesis, and their numbers will be part of the placement time.

Something seems wrong, we just need to narrow down where the bottleneck is.