Which uses more battery? Push email or sending/receiving?

[hgvidal]

Hey just had a quick question on which form of pulling my email drains more battery. I would think that its push email since its connected 24 hours? I have been using the seven beta program for push email but sometimes it refuses to work(Probably Gmails server thats at fault). So i was thinking of just setting up the POP3 gmail from the phone and having it send/receive every 30 minutes. Would this form use less battery or are they about the same??