I came across this the other day and tried to input my pc specifications and told me that my minimum wattage should be 600W, I own a OCZ ModXtreme 600W psu and the reviews on these things made by OCZ are not good. here is the lowdown on what I have:
MOTHERBOARD: asus p7p55d
CPU: Intel i5-750
VGA: 2x ATI(Asus) HD 5770s crossfired
RAM: 2x 2GB DDR3
1 CD/DVD RW optical drive
3 case fans
2 devices plugged into the USB ports (a Dlink wifi dongle and a mouse)
I think that my psu is barely sustaining the needs of my PC and I'm planning to add 2-3 more fans and a HDD drive to it. do you guys think it can still handle it after that? the psu calculator, made by ASUS tells me that when I add these things I will need a MINIMUM of 650W. some reviews say that the new series of VGA cards need less power but I want to be on the safe side.
EDIT: after reading the psu/ graphic card guide that's stickied, I got this:
Recommended 37 Amps on 12 volt rail for single card and 50 Amps for crossfire. This card can run on lesser this is just recommended and will be able to run with at least 30 Amps on 12 volt rail.
yes, crossfire will run fine on the 600W, but will the added components be fine along with the cards?
That minimum 650W PSU recommendation from the Asus calculator would be for an average PSU. If you have a OCZ ModXtreme PRO 600W it's above average, and probably out performs a whole bunch of budget 650W generic PSU.
What case do you have and why do you feel the need to add more case fans? System temps out of whack?
^ err, yep it says on the box "OCZ MOD X STREAM-PRO" I didn't know that there's a non-pro one I thought the PRO there was just for show lol (It's also modular, if that helps)
the temps are pretty high because of my budget case(thermaltake WingRS 301, not really a gaming case), I'm planning to change to the HAF X in a few days(to help cool the stacked VGA cards). and maybe replace the stock cooler on the CPU in the next few weeks, I'm busy and not really been gaming lately so I'm sure it'll survive til then.
There is zero difference in performance. Usually you pick a full tower case for an E-ATX motherboard on an ususually large number of HDDs or a tri/quad CF/SLI setup. Or maybe for extra room for internal water cooling.
Mid-towers cost less, take up less space and can keep a system just as cool, everything else being equal.