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SOLVED 750W enough for trifire?

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pwnmachine

Member
Joined
Nov 30, 2009
Hey all,

I recently got another 5xxx series card to keep my 5970 company. I am currently running a 750w Themaltake TR2 RX psu, which has been great.

However I am a bit weary of adding another card to my setup due to possibly not having enough power to supply the system.

Here are the specs relevant to psu specs:
9 x 120mm led fans
2 x 15w channel fan controllers
1 x 1tb 7200rpm drive
1 x 256gb ssd
1 x cd/dvd
2500k @ 4.8ghz 1.33v
asus p67 pro
5970 +5850 (900/1175)
1 pci-e xonar sound card
2 sets of cold cathodes


Using online power calculators I came up with this(90%):

power.jpg

I know these are not usually the best sources for information but its the best I can go on atm.

Any suggestions/recommendations?

I also have a 500w CM psu sitting around anyone know about the best way to setup redundant psus?
 
looks like the 5xxx series is about 150-200 watts, so with you drawing 580-630 watts (I did not check your work) already the answer is no. You need another power supply, I would recommend a 900+watt unit. Seasonic is great, so is corsair or antec
 
^^ I would like to avoid getting a new psu. I have a 500w CM psu just sitting here, any ideas on setting up a redundant system?
 
Well, I think I am just going to another psu, I can use my spare ones in other systems. 1000w sound right?
 
F(orget) dual PSU's... ANd especiialy forget NEWEGG reviews. Half the people on there are IDIOTS.

The TRr2 should be fine really. Not a lot of headroom but still fine.

Well, I think I am just going to another psu, I can use my spare ones in other systems. 1000w sound right?
For your setup, a quality 850W unit would be plenty.
 
I also have a pc power and cooling 750w silencer not being used. It is a better psu than the tr2, would that make a difference?
 
How many amps on the 12v rail(s) for each of the PSU's? I would go with the one that has more personally.
 
The silencer has 60amps and I cant find a spec for the TR2.

edit: tr2 is @ 56amps.

Would the 4amps justify me swapping out the whole psu? Plus the silencer is not modular.

Also seems like the tr2 has slightly higher efficiency (+86% vs +83%). Would it hurt to try? I obviously do not want to ruin anything but since the tr2 is still a high quality psu it wont blow, right?
 
^ Thanks for your help, I will try when I get home. I also have a power draw meter so I can keep tabs on the draw just in case it gets a bit to close for comfort.
 
A KillaWatt? Just remember that you need to take in to account efficiency from that reading at the wall. ;)
 
So, I got the card installed and everything seems like it is running fine. I am hovering around 600-700w, this seems a bit high. I played a bit of BF3 at ultra with gpu usage across all three from 80-100% , however when playing I noticed hitching and gpu usage dropping to 70%. Is this due to the microstuttering?
 
I ran furmark to stress out the gpus, and had no issues. Am I clear? :chair:
 

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Its tops out around 760w, I am using the built in power meter on my zalman mfc2. Now does the efficiency factor into it before or after?

eg. is my voltage actually (760w)(eff.)=(760)(~.86)= 635? Since I would assume my psu would have blown well before it hit 762w...


I found this showing the read voltage and the actual psu voltage:

26-Pwr-Table.png


So looks like even if it was showing 800w I would really be at (800)(0.86)=688w.
 
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