keep the 520w modstream or not

[Ashish]

I am building a computer for my brother and right now I am running into a debate with the PSU. Here are the specs on the computer

Koolance case
X2 processor (4400 or 4800)
7800 GTX
70gb raptor
an optical drive
DFI LP SLI-DR
OCZ 3200 Platinum rev2
Maybe a few extra fans
and about two CCL's

I just bought a 520 modstream from newegg and I already have a RMA reciept ready if I want to return it. Down the road I am thinkin about investing into another 7800 gtx. Now as you all know the Modstream is not a SLI psu so it only comes with a one PCIe connector. I am thinking about trading it for a 520w Powerstream.

Now my question will the 520 powerstream be able to take two 7800 gtx's or do I have to jump up to a 600 powerstream. At the same time the second 7800 is still a maybe. What do you all think?

 

[Ice Czar]

http://techreport.com/reviews/2005q2/geforce-7800gtx/index.x?pg=26
http://www.anandtech.com/video/showdoc.aspx?i=2451&p=20

of course Im overly conservative
and heavily power quality oriented
where the Powerstreams are generally better

but once your in the 600Watt price range I dont see their appeal over a PCP&C 510 SLi

 

[legcramp]

people run sli 6800ultra's with a 520watter powerstream... a 7800gtx uses less power than a 6800Ultra so I dont see the need for a 600 watt.... anyways.. I dont think ur modstream is up to the task for SLI 7800gtx... one would be fine though.

 

[Ashish]

so you all think if I get another 7800 GTX the 520 powerstream will be up to par? I would love a PC P&C but the price range is a little out of my league. Currently I think I should keep the modstream, since it is modular and should be enough for one card.

 

[legcramp]

eh grab one of the antec truepower 2's 550watter at newegg....it's in ur price range the amps on rach 12v rail is 19amps I ha ve one.. and it's a whopper

 

[Ice Czar]

http://www.xbitlabs.com/articles/other/display/atx-psu_10.html
specifically > http://www.xbitlabs.com/articles/other/display/atx-psu_11.html

vs

http://www.xbitlabs.com/articles/other/display/powerful-psu_9.html
specifically > http://www.xbitlabs.com/articles/other/display/powerful-psu_11.html


and as far as your crossload range goes
http://hardforum.com/showthread.php?t=844691
the 7800 GTX being somewhat less than
http://www.xbitlabs.com/misc/picture/?src=/images/video/ati-vs-nv-power/6800u_table-b.gif&1=1
and youll need to look up the processor
http://users.erols.com/chare/elec.htm
you convert watts to amps like
Watts divided by 12 (Volts) = Amps
and plug that into the calculator (type in the field)

plug in the basics, link her up and I'll give you my thoughts on the windage and factor in the post spinup worsecase along with convert the +12V to wattage

or you can per the instructions
drop the stuff that spins to 1\4 the amps
and convert the +12V amps like

Amps x 12 (Volts) = X number of watts from the +12V rail (since noth are ATX12V v1.3 hybrids hey have a single +12V rail and there is no need to figure each +12V rail seperately like in an ATX12V v2.0)
then take the combined wattage on the +3.3V & +5V as guven in the calculator and go up the crossload charts linked above and taking the +12V total wattage go over that will be the maximum draw and then back down to zero

 

[Toonage]

........where the Powerstreams are generally better
but once your in the 600Watt price range I dont see their appeal over a PCP&C 510 SLi

I would tend to agree with that now. I have a 600w PS sitting here unused because the wire management wasn't quite right for my latest setup. Very high quality, clean power, good warranty, SLI approved.........but the pcp&c takes home all the blue ribbons and will be my next psu after testing this Silverstone 650w Zeus (Got it because it was handy locally and I'm tired of waiting on parts shipments)