BTW, if torture wasn't effective it wouldn't be done.
That's not true at all. Historically most torture was a form of punishment. They were not trying to get information, they were getting even with enemies.
Its effectiveness is also dependent on a goal. If you want a confession, genuine or not, torture will work. But a confession by torture is really worthless. Therefore I deem any torture to get an admission of guilt, as ineffective.
If you mean torturing to get intelligence, its not all that effective. They will make shit up to appease you.