WP handles this a lot better. I'll explain why:
With MT, your pages are "re-created" each tim you post. This results in a big surge of CPU power, and then a lot less during normal traffic. If you have multiple postings per minute, it takes up a LOT of CPU power. However, if you post once a week - MT in this regard is actually 'faster' or less harsh on the CPU.
With WP, each pages is "re-created" each time someone view it - however it takes far less CPU power. So, whether you post a new entry or not - the same amount of CPU power is used. It's more dependent on traffic. In this regard - WP is much faster than MT.
So, if you were to break it down:
MT's CPU usage is dependent on amount of postings/comments
WP's CPU usage is dependent on traffic.