SST-ST60F/ST75F not enough?

[Blue Fox]

So I rebuilt my server using the power supply I had previously used (SST-ST60F) and it was fine when I had 12 drives. When I swapped out some drives and wound up with 13 total, it was still fine. Now that I've added the 3 I had previously taken out (up to 16 drives), the server will turn on for a second and turn off. Unplugging a few drives solves this (doesn't matter which drives I unplug). I figured that it might be a little too much for the PSU, so I bought a SST-ST75F to try out, but it too would only power on for a second with all the drives attached. I would do staggered startup, but the power adapters I'm using for the drives don't provide the 3.3v line required for that. Apart from moving up to something larger (or 2 power supplies), I have no idea what the solution could be...any ideas?

Server specs (picture):
Dual 2.4ghz Xeons (Gallatin)
1.5gb DDR266 (6 sticks)
15 Seagate 7200.10 drives (12 attached to an Areca 1130ML)
Random boot drive