Please help with this power supply.

264W is the max. power available on the two 12v rails combined. See it listed on the label. 264W / 12v = 22 amps. total available on the two 12v rails combined. If you were using one 12v rail you could use up to 16 amps. on that rail. The TOTAL power the PSU can produce is 300W but if you use power from all of the rails, 3.3v, 5v and 12v the total available is 300W not what each individual rail can provide separately on it's own.

As far as PSUs are concerned, be informed. Before you buy any PSU read accurate, objective PSU reviews at reputable sites such as www.jonnyguru.com or www.hardwaresecrets.com on the EXACT model PSU that you are interested in as some brands have good and poor quality PSUs.

You can also get an accurate rating of how much PSU power is required for your current or future system at the PSU calculator link below. Once you know the total PSU watts required then you need to confirm that the 12v rail has enough amps. to support your Vid card(s) and the rest of the PC system.

There are several websites that show the Vid card power consumption in watts. Divide the watts by 12 to determine the amps. required on the 12v rail(s). Add 15 amps for the rest of the PC on the 12v rail and you now know the Minimum total 12v rail amps required under full load. It's best to have at least 5-10 amps. reserve on the 12v rail available under full load so the PSU is not loaded to 100%.

It's also worth noting that people often misunderstand the 80% power rating. This is a rating of the PSU's energy efficiency not it's output. 80% plus PSUs use less grid power to produce the same PC power. If it's 80% Bronze, Silver or Gold the cost savings on electricity is pretty small between Bronze, Silver and Gold unless you are paying very high rates for electricity so any 80% rated quality PSU is fine even if not Gold. For those who leave their PC on 24/7 a quality 80% PSU is a good investment.


http://extreme.outervision.com/psucalculatorlite.jsp

http://www.guru3d.com/article/geforce-gtx-560-ti-sli-re...

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_5...

Why absolutely










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NOT.
That PSU is a generic turd that is not 80+ nor from a reputable power supply company/maker. It will power a Phenom II 955 BE and a 6850 for ,give or take, 5 seconds before exploding due to it cannot handling the load. When that happens, your computer is at risk of being destroyed due to the fact the PSU exploded.


Give us the name of the case and some pictures so we can decide if you can fit a standard ATX PSU in it. If it fits a 6850 then it should usually fit a ATX PSU.
If not then look for the Seasonic mATX PSU's.


Always look for PSU's from reputable companies such as Seasonic, XFX, Corsair, Antec and a select few others for their units are quality made, backed by warranty the companies observe, and is well tested by reputable reviewers such as jonnyguru and hardoc.

Thanks for the detailed reply, beenthere. That answers most of my questions.

lilotimz,
According to the calculator poster by beenthere, the recommended PSU for the system i have in mind would be ~310W and min would be 257W. Thats with Phenom II 955 BE, 6850, 2 DDR3 sticks, "high end" mobo and an SSD.
While it would certainly be pushing the 300w PSU that i have, would it really "explode in 5 seconds" ?

This is the case im using:
http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...
A full size video card will fit in it, and it does use micro ATX PSU.

I'd love to use a good PSU from a reputable company, but there are none available in mATX form that offer a significant improvement. The seasonic mATX only has 6 more watts on 12v rails.
There's this one:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
It has a lot more power but the manufacturer is "questionable", and i dont know if its worth ~100 bucks.

Are there any psu's that can fit inside a 3.5" bay that could power the 6850 while the included 300w PSU powers everything else?

Thanks again!

I can't open the link to newegg.CA sites so you got to tell me model name.

Power supplies are not all made equal. There is no set standard on how they label their psu's nor is there a standard for how psu's are rated.

300W's could be the max output or it could be continuous but the fact is that this is a no name PSU that nobody knows. A Seasonic "might" have 6w more on the 12v rails but it's a PROVEN PSU that can put out all if not MORE than what it claims to be able to. Not to mention, the parts inside of it is usually rated at 50 Celsius which means longer longevity and quality. This cheap junk will prolly have cheap components rated at 20 Celsius or 25 Celsius that degrades considerably when it's above that temperature.

As I said, Seasonic, XFX, Antec, Corsair and select models from other companies such as PC&P, Kingwin, OCZ, Thermaltake are recommended because they have QUALITY parts and is REVIEWED by INDEPENDENT and TRUSTWORTHY people who test it to see if they can reach their rated wattage and still remain STABLE.

I trust seasonic more than any other psu manufacturer out there because they're consistently putting out quality products and their PSU's show it. Corsair AX series? Their based off Seasonic X series. XFX units? Based off Seasonic units. High end Antec Units? Yup seasonic.

What matters most in a power supply is the quality of it because it might be rated a 600w unit but when it fails in 5 seconds and blows up, you're the one that's going to lose.

Also I wouldn't run anything with a 6850 and a Phenom II 955be with less than an Antec EA380D unit...