[hatrix216]

So currently I have this PSU: http://www.newegg.com/Product/Product.aspx?Item=N82E16817148022

Now I believe it barely meets the demands of my current build, with an FX-8350 and an XFX HD 7850.

I'm upgrading my graphics card, and instead of crossfiring another 7850, I've decided to upgrade to an HD 7950. Now my question is will this PSU be sufficient for my build ?

This is the one I was considering: http://www.newegg.com/Product/Product.aspx?Item=N82E16817182277

I'm trying to only spend around that price for the PSU, as my cart with the PSU and HD 7950 totals $339.72. I really don't want to go very much over that total.

Obviously I'm more concerned with amperage output on the 12v rail(s) then overall wattage.

 

[crimsontears809739]

Your current 680W PSU is adequate for that card.

With a 7850 and a FX-8350, a 450 watt power supply would be "bearly" adequate. A 670 watt power supply is plenty.

Your going from a 22A + 24A 12V rail power supply (46A total) to another 46A 12V rail power supply.

Now your card only had x1 6 pin connector. That maximum power out of one of those 6 pin 12V connector is 75 watts. Therefore 75/12 = 6 amps. You video card won't draw more than 6 amps off any voltage rail via the PCI-E power connector. That card has a peak power consumption of under load is 100 watts. (100-75)/12 = 2 amps. You card will draw 2 amps through the motherboard.

That's around 8 amps total on the 12V rail for your GPU.

You CPU is 125 watts. That around 10 amps from your CPU.

That's a little over 18 amps on the 12V rails total for CPU + GPU. Each voltage rails is 22A, and I assume the current power supply puts the +12VDC for the motherboard and PCI-E power connector on different voltage rails.

I don't see any problems with your existing power supply.

Is my math wrong? Please show me where your math is coming from.

Now, if you went with a SLi system...then yeah...there might be problems with balancing current on your voltage rails. But, for a single card system your definitely fine with your current PSU.

 

[hatrix216]

My HD 7850 actually requires two 6 pin connections.

See I made another thread here: http://www.overclock.net/t/1366191/crossfire-hd-7850-or-upgrade-to-hd-7950

I was trying to decide whether to crossfire another HD 7850 or upgrade to an HD 7950. Some people in that thread said my current power supply might not be enough for the 7950.

My power supply isn't very high quality, so I doubt it's really pushing out 680 watts. Also, if you look at the specs on the official products website, I'm not so sure about the listed amperage outputs on the 12v rails.

I mean if you REALLY think my current power supply will be fine if I upgrade to an HD 7950, great. It would have the same amount of 6 pin connections on the card as my 7850, since they both require two.

And I don't necessarily think your math is wrong, seems right. But regardless, both my current card and an upgrade to a 7950 would require two 6 pin connections. My HD 7850 seems to be the only one that requires two 6 pins, oddly enough.

It's this card: http://www.newegg.com/Product/Product.aspx?Item=N82E16814150609

EDIT:

Actually, I think I've decided to go a different route. I'm going to crossfire another HD 7850, and upgrade my power supply to this one (which will give me a bit of future proofing for any other upgrades or rebuilds): http://www.newegg.com/Product/Product.aspx?Item=N82E16817182133

It gives me enough 6 pin connections for my two cards, which I couldn't seem to find with lower wattage power supplies that still were enough watts and amps for the crossfire setup.

 

[hatrix216]

I already made a decision and went ahead and purchased another HD 7850 and a new PSU, so this thread can die now. Thanks for any help though crimsontears.

 

[TwoCables]

Yeah, at $69.99, it's hard to beat!

 

[contrvlr]

Quote:

Originally Posted by crimsontears809739

Your current 680W PSU is adequate for that card.

With a 7850 and a FX-8350, a 450 watt power supply would be "bearly" adequate. A 670 watt power supply is plenty.

Your going from a 22A + 24A 12V rail power supply (46A total) to another 46A 12V rail power supply.

Is my math wrong? Please show me where your math is coming from.

OP's existing psu wouldn't even be considered a 450 watt unit in todays world
The 12v rails have a combined output of just under 26 amps
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=78

 

[TwoCables]

Quote:

Originally Posted by contrvlr

OP's existing psu wouldn't even be considered a 450 watt unit in todays world
The 12v rails have a combined output of just under 26 amps
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=78

That's even a little less than what I was thinking:

Quote:

Originally Posted by TwoCables

Wow:

http://www.apevia.com/productsInfo.asp?KEY=ATX-AS680W-BL

It looks to me like they're trying to say that the +12V has a capacity of only 330W. I mean, let's look at it very carefully:

When you combine the +5V and +3.3V, you get 330W. Fair enough.

When you combine the +12V, +5V, and +3.3V (that is, when you add in the +12V), you get 660W. That's an additional 330W, and the only difference is now we have the +12V in the mix.

If this PSU's +12V capacity really is 330W, then it's just a low-quality 350W power supply at best.

When I see specification charts like this, all I see is evidence of a very low quality PSU that should be avoided at all costs - especially for modern-day systems.

 

[hatrix216]

Yea no surprise there, I bought the PSU rather quickly without doing research because my old one had died on me and I'm sure you all know not having your desktop running is unbearable. I also didn't have much to spend at the time but it still probably wasn't the best option for the money.

I'll probably just keep it as a backup PSU or try to sell it for a little bit of money, even though it's only $55 new.

Either way what I'm upgrading too should be more than enough. And at $70 shipped it's a damn deal to me: http://www.newegg.com/Product/Product.aspx?Item=N82E16817182133

 

[TwoCables]

Sell your Apevia to an enemy. You know, someone who deserves a junker of a PSU.

 

[OddGusta]

Yeah, I almost got that, then decided against it. Burned a StealthXStream refurb, rocking a ZT now.

 

[crimsontears809739]

Holy crap, I didn't realize that. I just looked at the 12V amperage on newegg.com.

I did not bother to go to Apevia's website and see the whole "nominal current", nor read that review about the actual current output.

My sincerest apologies to OP.

I redid my math using the power supplies "actual" power output.

"But then they list a maximum of 22A and 24A. Maximum means, the regulators can go up that high, but don't expect clean voltage and if it stays that high for too long, expect fireworks. How do I know this? Look at the combined maximum wattage for the two 12V rails. It's only 310W."

All i can say is "Woops". Yeah, that will not work.

Sorry.

 

[hatrix216]

Oh don't worry about it. I'm rocking a Rosewill HIVE-750 now for my crossfire setup.