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Need psu help

Last response: in Graphics & Displays
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November 10, 2010 9:35:25 AM

(need psu help)

i3 540
p7h55v
2gb
80 gb for now
psu cm 335 with 420 watts
i was going for gts 450 but now ive changes my mind towards 5770 which seems to be a faster one

now my question is :
if 5770 need 108 watts on max load, can i use only 220 watts psu with it or it is must to use 460 watts atleast as on 5770 specifications it is written that it need minimun psu of 450 watts and why?

More about : psu

November 10, 2010 9:44:49 AM

The graphic card is not the only part which uses electricity, other parts like the cooling fans, the CPU, HDD and other accessories also take up Watts from your PSU. No, you cant run your whole PC on just the 220watts with HD 5770. you should be okay with the CM 420 watts PSU.
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a b U Graphics card
November 10, 2010 11:48:45 AM

I wouldn't dismiss the GTS 450 so early. Heaps and heaps of overclock room bring it very close in performance to a 5770. Ok, so you have to OC the 450 to get close to the 5770 at stock, and when you OC the 5770 it will far outstrip the 450....but I think we're talking about a difference of 5 frames in most games, maybe 8. That's not too huge! I'm running a 450 with a 400W PSU (a very good one mind you), and for games performance it's absolutely great. Just a thought!
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a b U Graphics card
November 10, 2010 12:01:11 PM

The ThermalMaster 420 watt psu is a piece of crap that only provides 16 amps to the 12v rail, for comparison, a good quality 400-450 watt psu can provide 28-33 amps on the 12v.
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November 10, 2010 12:26:11 PM

Aah man, i even dont know any thing about amps & rails & also none of my friends i asked. :( 
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Anonymous
a b U Graphics card
November 10, 2010 12:43:26 PM

Edenkham you did a question very difficult to be covered in such a sort notice. Ati is giving these results to cover all differed system configurations and differed settings on the hardware and I can verify their results because they cover my case. Q6600 OCed in 3.30, HD5770 OCed in 950Mhz 6 satta ii in raid 0 the extra amount from this is 51,6 watts (8,5-8,6 per disk) someone with raptor hard disks volume will hit higher value than me add and your dvd rom I have 2 the bagged goes high.
I can verify the results of ati and amd because they cover my case, they doing it to cover all the cases. Their test in CF 5770 you can see it in here:

http://sites.amd.com/us/game/products/certified/Pages/c...

HD5770 appears only in 850 PSUs!!?? The thing is they are right there is no psu that can hold a steady power in 12 volts trail if you connect it to a digital polymeter you goanna see the Ambers, Volts and finally watts to go up and down if you do a graph you will never have a stable line. I had 650 Silver, I moved to 650 bronze just to minimize the gap from the lowers value in watts and the highest value in watts so I can be sure there is no chance to loose even 0.001 from the lower value of volt the PSU can believer to my 12V path and make the graph to look more like a line. I was in 369 watts max but when I forced to OC my Q6600 to 3.30 even if I use only 1.4025 settings in the bios the cpuz you can see it here:

http://admins.bnb.gr//~giatrakis/idle.jpg
(idle after the extrem test 4Gbytes memory posted in public.)

The Q6600 by itself breaks 146watts when I run it in 0 memory test! And know I idle to 198-207 watts and it hits 450watts maximum! I got this peak only for a moment but it happen didn’t managed to capture it. The additional watts are from raid the disk are having 8,5-8,6 watts max each x 6 = 51.6 watts when the run in full and basically it hit 450 watts only in 0 memory test when the raid reach the maximum speed to cover fast the large amount of data moving to the swap file 350Mb/ps it was 8Gbyte ram + 9 Gbyte swap file = 17Gbytes usage…

So for the CF HD5770 I need the 850 bronze as ATI-AMD suggest and I was thinking a 875 watts bronze Thermaltake can do it for me but after delluser1 pasted a 32nm system 500 watts peak I thinking seriously in the new system to go for 1200watts silver Thermaltake at list I will never drop my lowest limit in a value that may cost me a downgrade for sec my raid volume, cpu, dvds and everything you getting it? Basically I have a system already that do even a dvd copy at the fly (+100watts or more) while I’m running prime95, furmark 1.8, extreme EXEPTION the 0 memory test in there is impossible to copy a dvd on the fly even the mouse has problem to move in some systems.

I also have external satta ii for the storage of image connected (raid) 1 usb stick.

Ps: this is the 4Gbytes extrem test see the HD5770 working in full:
http://admins.bnb.gr/~giatrakis/Prime-Turture-4Gbytes-F...
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a b U Graphics card
November 10, 2010 2:18:01 PM

edenkhan said:
Aah man, i even dont know any thing about amps & rails & also none of my friends i asked. :( 


To explain things briefly, your power supply uses different "rails" to power different things. Look at the side of your power supply and you'll see the different rails: +12v, -12V, +5V, -5V etc. Corresponding to those rails are the amps they can supply, e.g. 28A.

Here's an example:
http://img361.imageshack.us/i/img3480.jpg/

Sometimes a good PSU will have multiple 12V rails, these are good and provide good system stability. The one in the picture has 4 12V rails, which is great.

The graphics card will run off the 12V rail, so the more amps your PSU provides the more power you can give your card. Very powerful cards are very electricity thirsty, that's just a fact. If you don't want to worry about all of the above, it is possible to get a card like the 5670 which performs worse than the 5770 but requires much less power and no external connector.
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