Default drive strengths for Stratix III and Cyclone III

If you set min drive strength as default, you could violate timing at your receiver or underdrive your transmission line and end up not recognizing 1's/0's at the receiver. Not good.

I would rather have things work by default than having to think about everything. If Altera can provide me with "likely to work" settings, I'll take it. Then I can focus my debug and engineering time on the problems instead of having to check every little thing. Nowadays these chips are too complicated to do that.

Also, the vast majority of designers use 50ohm transmission lines, so setting the default to 50ohm makes sense.