Assuming a sealed system, pumps should continue to work, even though they're notably bad at suction.
However...
- you'd be reducing the boiling point of water and increasing the likelihood of cavitation in the pump
- having dealt with vacuum systems, it's actually a lot easier to keep water (especially the low pressure water we use) in than keeping air out
- beats me if this'd reduce waterblock heat transfer efficiency. there may be a relationship between the absolute force with which a water molecule is forced against a baseplate and the amount of heat transferred to it - but only some waterblocks seem to depend on this.
- I'm guessing there's a major effect that's right in front of me that I'm missing...
Why not set up a system and see - let us all know what you find. Might as well add some of those anti oxidants you were asking about earlier to see what they'd do, too
