[adgjlsfhk1]

no (in both directions). lots of np/exp problems paralize well and you can be in NC and parallelize really inefficiently (e.g. you can get a 10x speedup, but you need 1000000x the hardware). the better framing is that NC is the class of efficient algorithms that can be sped up near arbitrarily by parallelization

[osti]

Hmm your last sentence seems to exactly agree that it's a class of algos that parallelize well? What does sped up arbitrarily mean? It's still polynomial speed up right?

[chowells]

It's a difference of degree. People expect something that "parallelizes well" to show near 1-to-1 speedup. Double the hardware, double the speed. This is "you can always speed it up, but the hardware requirements can increase at any polynomial rate".

[osti]

Ah got it. Reread previous comment and that makes sense.

[dragontamer]

Yeah it's more of "on a hypothetical infinitely parallel computer, you'll get a big speedup'.

Which is still useful if you can prove a problem is in NC. It's just not quite as strong as people make it out to be.