How much extra load does a 12V pump put on a PSU?

Obviously it depends on the pump, but how much extra load will the Swiftech MCP600 (AquaExtreme 50Z) 12V pumps put on a PSU?

Right now I'm running the sytem in my sig on the Antec True 430Watt. Voltages seem OK, but the Vcore does drop under load, not sure if its a PSU or mobo problem though.
After a 25 minutes Prime95 torture test MBM5 reports voltage low's of:
12V - 11.86
5V - 4.95
3V - 3.25
Vcore(set at 1.7) - 1.63

Do you think I'd be ok adding a pump to the system?

Well i know its yourem otherboard undervolting the cpu my NF7-S did this also and so does most of everyone else's i know.

If youre getting a low of 11.86v already then adding a pump will probly make it go down alotm ore by how much im unsure, how much voltage does that pump use to can get an Idea of how much youre 12v will go down.

You have to figure out what the load is now and see how much wattage is left over.

I have a 300 watt supply running dual 2200+ processors, GeForce FX 5500, WD 80gb drive, 1 cd burner, 4 fans, and a DangerDen D4 pump (18 watts.) If I can do all that on 300 watts then 430 watts should certainly handle the load of the pump...unless you've got some very power-hungry components in that machine.

9 Watts is the 'nominal power' on this pump. Which is less than I thought it would be...

You shouldnt see much of a drop it may go from like 11.86v to like 11.80v maybe not even that