In general, most are around 800+.
There are some low chill varieties though. Sandy pears aren't worth eating (great for cooking though), unless pollinated by a Kieffer or Barlett, but they have a reliable crop every year. My few low chill pears only make a crop every other year. I could probably fix that with grafting but won't bother. Pears are cheap in the markets here, and the ones I grow I only do because I can say I am growing them and the trees are very eerie looking (cool factor) when properly trained.