Which PSU is recommended for overclocked xfx 5870

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I have corsair 550w VX connected 5870.

I have sight problem like

bad 3D performance (other possible reason)
crashing games like Cryis and Mirror Edge, few times, abnormal graphic on resident evil 5 when using 0xAA.
black lines constantly blinking on second monitor only if i overclock using overdrive


I set ATI catalyst to balance, where all setting is maximum apart from application is set on AAF and AA. I set AAF to max and AA to 4x. Screen resolution 1920x 1080 through hdmi.

How many amp i need for to overclock from 1200 to 1300 mhz on memory clock and 850 to 900 mhz, and also get rid of these problem and have better performance.

 

Harrisson

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Corsair 550W is more than enough for 5870, hell, it would run two of them just fine. Your issues are with software (highly likely) or some faulty HW (happens, but first check soft side).
 


Nawww man.

A 5870 consumes about as much power as a GTX285, and two of them consumes more power than a GTX295.

For two of them, he'd need a quality 750watt PSU.
 

surda

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they consume too much power, it has double transistors as their previous 4870, if u got one card, you'll be good with 550W (with good quality i recommend corsair), but if u want to crosfire then u gotta get a 750W or maybe 800W Corsair PSU.
 

Harrisson

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W requirement is overrated, my firm is building custom computers, and usually quality PSU req is much lower than "recommended".

For example: http://www.hexus.net/content/item.php?item=20354&page=6

2 x 5870 system uses 357W, its better if its doesnt go above 80% of PSU W, thats 440W. As you can see even with X2 you have enough supply with Corsair 550W, what to speak of single card. BTW, 4870 X2 uses ~361W, and runs just fine on Corsair 520W (tested). That said, its always better to go for more powerfull PSU/etc if your pocket allows, but if you already have enough power, there is no need for unnecessary upgrade.
 


The problem is, hexus is showing the computer at load, but not at "full load." Tomshardware showed that two ATI 5870s used 561 watts in crossfire at full load. http://www.tomshardware.com/reviews/radeon-hd-5870,2422-20.html

So at full load, two 5870s would blow out a corsair550 watt PSU.

As for a 4870x2...I would not want to run it on a 520watt PSU considering that the recommended PSU for a single 4870 is 500watts (abet overestimated). And tomshardware shows the 4870x2 uses 490 watts at full load.

I'm sure a 4870x2 or a 2x5870x2 "runs fine" on a 520/550watt PSU - but only when it's idle or during non-intensive use.

But if you run a benchmark or something more intensive then you risk destroying your power supply and blowing out components. And if a system can't run a benchmark without issues, then the system is not considered to be stable.
 

Harrisson

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It depends on the system, for example Toms had i7 OCed to 4GHz, but you are right that with some PCs more powerful PSU is needed.


Client had Corsair 520W, so he tested with new 4870 X2 if he needed PSU upgrade, he didnt. And yes, he plays a lot. So once again - it depends on more factors than "buy 750W PSU anyway".

Back to the topic - for one card Corsair 550W is more than enough.
 


A 550watt for 1 5870 is more than enough. I said buy a 750watt for two of them in crossfire. Trying to run two of them with a 550watt is playing Russian Roulette.
 

smoggy12345

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550 watt IS pushing it close.

You need to add up your system wattage to really determine if you need the upgrade.

For example, i have a 600watt PSU and run 2 8800GTS' jus fine and they use quite alot of power (probs not far off 2x5870's at all)

Processor = 65, 90, 125 watt?

Each harddrive uses roughly 7watt

Then your graphics card = 189watt??? that right for the 5870?

so worst case scenario:

125watt processor + 2 x 7watt harddrive + 2 x 189watt (for 2 5870's)= 517watt

So your PSU is fine...although you are pushing it a bit...if you wanted 2 of them overclocked.
 

surda

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no it will not be stable if it does not get enogh Watts and will run at lower speed(gives less performance than what it should be).

BlueScreenDeath is right as he mention'd not only to look at how much your graphics card needs but also you have to add the other components Watts as well such as the cpu ram harddsik mobo everything, so getting one higher than what all your components needs is better for your compenonets to get the amonts of Watts they need and be stable.

seriously many people think of a power supply as just a power source even though it is the most important part in your computer, without a good quality power supply then all your components are as good as old 1998 computer.
 

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