Please HELP: What is the max # of HDs this PS can handle?

[InGearX]

I have a Dell PowerEdge SC420

I looked on the PS unit and it has:

MODEL NO: PS-6311-1DFS

DC OUTPUT 305W

+5V === / 22A MAX
+5V(FD) === / 2A MAX
+12V - A === / 18A MAX

-12V === / 1A MAX
+3.3 === / 17A MAX
+12V - B === / 18A MAX

COMBINED POWER ON +3.3V AND +5V NOT EXCEED 150W
COMBINED POWER ON +12V-A AND 12V-B NOT EXCEED 264W
MAX. CONTINUOUS TOTAL DC OUTPUT POWER SHALL NOT EXCEED 305W

Image: http://www.ingearx.info/temp/My_20Dell_20PowerEdge_20SC420_20PS-6311-1DFS_1_.jpg

I looked at the hard drives and they are:
Seagate: (I have 4 of these)
+5V 0.75A
+12V 0.35A

Maxtor: (I have 6 of these)
+5V 740mA
+12 1500mA

Leading out of PS:
cord with: 2 SATA power connectors
cord with: 1 PATA and 1 for floppy drive
cord with: 1 power connector w. 6 sockets (5 have connectors inside) and 2 PATA power connectors

I also placed 3 PCI IDE expansion cards in the server.

My question is - what is the proper way to do the math to find out the maximum number of hard drives that the PS can support?
And do you think it is safe to plug all of those 10 hard drives that I have?

Thank you all very much...

 

[crydee]

You will need to list your complete specs.. and assuming you max load everything on the system >_<

 

[Hyperlite]

yeah we gotta know what else is on the system. @ 305w max, i wouldnt say more than two or three if th rest of the system is pretty average/low end

 

[InGearX]

Thank you all for your help support.dell.com gave odd asp .net error...

So manually my specs are:
P4 2.8GHz, 2x512MB RDRAM, no video card (but AGP slot is present), 3/3 PCI slots have PCI IDE cards, 1 DVDRW drive that is it;

The rest - I want to hook up as many HDs as I can... what do you think?

http://www.extreme.outervision.com/PSUEngine estimates I can have 9 HDs - but look at the #of Watt difference in consumption of Maxtor and Seagate...