PSU gold vs bronze question

[droopyRO]

I have a 3770k, two GTX660, Asus Z77V-pro, two HDD and other less power hungry componenets all powerd by a Cougar 550W power supply 24+20A 12v rails 80 plus Bronze.
Since its about 3 years old i want to buy another one.
My budget is about 100-130 euros should i buy a Bronze 700-800W PSU or a Gold 600-650W PSU ? i will want to overclock the system but nothing extreme 4.2-4.5 Ghz on the CPU and about 10-15% on the graphic cards.
Thank you.

 

[NdMk2o1o]

I have a 3770k, two GTX660, Asus Z77V-pro, two HDD and other less power hungry componenets all powerd by a Cougar 550W power supply 24+20A 12v rails 80 plus Bronze.
Since its about 3 years old i want to buy another one.
My budget is about 100-130 euros should i buy a Bronze 700-800W PSU or a Gold 600-650W PSU ? i will want to overclock the system but nothing extreme 4.2-4.5 Ghz on the CPU and about 10-15% on the graphic cards.
Thank you.

Definitely the gold 600-650w that is more than ample for your system overclocked and would even support a 2nd 660 down the line.

 

[BarbaricSoul]

Personally, I'd go for the higher wattage, but that's only because I feel a dual GPU set up should have at least 750 watts.

 

[THE_EGG]

Definitely the gold 600-650w that is more than ample for your system overclocked and would even support a 2nd 660 down the line.

OP already has 2 0.o

600-650W would be my sensible recommendation. But personally I'd go for a bronze 750W or something to be safe. I'm still running a bronze 1kw from about 3-4 years ago.

 

[RCoon]

He already has two 660's. His system would probably use 500watts on GPU's and CPU plus RAM. I think 650w Gold would work, but as a general rule of thumb, I always go for 750w minimum for dual GPU setups. Then again I run higher power cards.

 

[NdMk2o1o]

OP already has 2 0.o

600-650W would be my sensible recommendation. But personally I'd go for a bronze 750W or something to be safe. I'm still running a bronze 1kw from about 3-4 years ago.

#In that case i'd go with the top end of 650w rather than 600w, though my choice would still be this and gold rather than higher wattage, I'd imagine when gaming it would be drawing around 500w

 

[Shou Miko]

He already has two 660's. His system would probably use 500watts on GPU's and CPU plus RAM. I think 650w Gold would work, but as a general rule of thumb, I always go for 750w minimum for dual GPU setups. Then again I run higher power cards.

even with his system now, he can go 600watt 80plus Gold and won't have any issues, bcs he is using a 550watt now, but go after SeaSonic if u can to get their Gaming Series or if u got the money their X-Series, i got a SeaSonic X-760 and i am happy with it ^^

 

[de.das.dude]

the difference between bronze and gold is the efficiency at different loads.
titanium is the best. gold is in the middle. which is around 90% efficient at best.
bronze is about 85% efficient at best

details here
http://www.plugloadsolutions.com/80PlusPowerSupplies.aspx

i would go with the 750W too, as the 650W would be cutting it close in my opinion.

 

[droopyRO]

Ok thanks for answering all, i will get a 750W PSU then. 10q

 

[Frag_Maniac]

It's not just about wattage, but amperage as well. You basically want around 36A on the 12v rails for dual SLI 660. Even the HEC built Cougar Power 550CM has 40A on the 12v rails.

http://forums.guru3d.com/showthread.php?t=205763

EVGA and MSI both suggest about 1.5 times the recommended wattage/amperage for dual SLI. Both say 24A and 450W for one 660, so dual SLI rec would be roughly 36A and 700W.

As for Gold vs Bronze, the Gold will run a little more power efficient with less energy cost on your power bill over time, and often the Gold ones also have quality Japanese capacitors vs Chinese ones, so they typically last longer, are more stable, and can sustain high power loads with less heat buildup. It all depends on the quality of the unit though. Not all Gold PSUs are made to the same quality standards. The Bronze, Silver, Gold etc, ratings are really only an output reference as far as percentage of consumed current being output.

I went for the oft overlooked Silver rating myself, and I'm very happy with what I got. I referenced jonnyGURU for test results because I know their torture test is very revealing. Mine got a 10/10 performance rating from them, which isn't very common, esp in the price to wattage range I was looking at.

 

[Jack1n]

Your fine with the PSU you have right now.

 

[McSteel]

No, man! You should totally get a 1200W gold-rated PSU. Totally. One can never be too safe!

Now, with cynical sarcasm out of the way, we can discuss your actual needs.

Your GPUs use about 180W max, each, when OC'd 10-15%. Your CPU won't use more than 120W max at ~1.25V and 4.5 GHz. You didn't specify which Cougar 550W PSU you have, but they're all effectively single-rail, as OCP trip point is set between 39 and 42A on each 12V rail, which is pretty much the full 12V capacity of the unit. You'd only draw a combined 40A from the 12V rails if you totally unrealistically loaded everything down to it's absolute max. This never actually happens in actual usage.

3 years of service is nothing to be afraid of, these PSUs should last at least 5 before there's any chance that something's starting to wear out. The first thing to go in these PSUs is the fan, followed closely by the secondary filter capacitors (especially 5VSB and 12V ones). You still have ways to go before this becomes a problem.

Bottom line, I wouldn't change my PSU yet if I were you.

 

[TheoneandonlyMrK]

No, man! You should totally get a 1200W gold-rated PSU. Totally. One can never be too safe!

Now, with cynical sarcasm out of the way, we can discuss your actual needs.

Your GPUs use about 180W max, each, when OC'd 10-15%. Your CPU won't use more than 120W max at ~1.25V and 4.5 GHz. You didn't specify which Cougar 550W PSU you have, but they're all effectively single-rail, as OCP trip point is set between 39 and 42A on each 12V rail, which is pretty much the full 12V capacity of the unit. You'd only draw a combined 40A from the 12V rails if you totally unrealistically loaded everything down to it's absolute max. This never actually happens in actual usage.

3 years of service is nothing to be afraid of, these PSUs should last at least 5 before there's any chance that something's starting to wear out. The first thing to go in these PSUs is the fan, followed closely by the secondary filter capacitors (especially 5VSB and 12V ones). You still have ways to go before this becomes a problem.

Bottom line, I wouldn't change my PSU yet if I were you.

Balls ,, get the 1200 , future proof

Im a bit tired but efficiency wise at low watts a 1200 should be more efficient anyway wouldn't it.

 

[McSteel]

In theory, it should be. It depends on the efficiency curves of the specific models compared, of course, but in general, a 1.2kW Gold unit should be more efficient, since at ~480W max load it nears it's peak efficiency band, while the 550W Bronze unit is exiting it. Probably ~88% for the Gold one vs ~84% for the Bronze one.

If you took an Andyson-made "Gold" unit and a Seasonic- or Delta-made Bronze unit, I think they'd be just about on par.

Y'all do realize I was kidding about the > 1kW stuff, right?

 

[Jstn7477]

Balls ,, get the 1200 , future proof

Im a bit tired but efficiency wise at low watts a 1200 should be more efficient anyway wouldn't it.

Assuming the computer is constantly using 500w (which is unlikely unless they are distributed computing) then probably, but at idle it's going to be 100w or less.

To the OP: either keep your current PSU or upgrade to a higher efficiency model. Buying a higher wattage model at bronze efficiency when your current PSU works fine is pointless.

 

[AsRock]

Personally, I'd go for the higher wattage, but that's only because I feel a dual GPU set up should have at least 750 watts.

He already has two 660's. His system would probably use 500watts on GPU's and CPU plus RAM. I think 650w Gold would work, but as a general rule of thumb, I always go for 750w minimum for dual GPU setups. Then again I run higher power cards.

Same here 750w PSU for dual cards. Less strain on the PSU and less heat due to it.

And imo a single rail Seasonic PSU some even carry a 7 year warranty.

And find a few reviews done by sites to see the efficiency at different loads although you need to know what load stats your comp is and guessing and sites are normally wrong so might be worth picking up a kill a watt from newegg or amazon.