Yup, I thought I was mistaken... I couldn't remember which one was the one that had better preventative properties, but I do recall watching something on the history channel about plate and chainmail armours, and which was most effective.
Now that I think about it, I definitely did get it the wrong way around. Chainmail was more effective at preventing slashing damage, also in due part because it was lighter and allowed for more agile movement (despite still weighing a LOT). Likely if you simply swung at a stationary target, chainmail probably wasn't that effective at stopping the blade, despite a lot of the blade's energy being dispersed among several chain links - the links would break and the armour would become vulnerable at that point (as well as allowing the rest of the blade energy to dissipate into the body of the wearer). Where as a plate armour would take the bulk of the energy and dent the armour instead of break the chains... but, you wouldn't typically be swinging at a stationary target, would you?
Plate armour on the other hand had better properties for preventing piercing damage, which is why plate armour was worn for jousting, and generally for heavy cavalry to help combat spear attacks. A fully plate-armoured infantry unit wasn't something you'd expect to find due to the sheer inability to remain mobile.