well, you're right about efficiency decreasing over time, but you're wrong about it decreasing to the point where it won't provide enough power. 350w is plenty for that set-up, and will be for years, provided the amperage is sufficient. as i've already stated. the fact that you have a 750w psu for what you're actually running is testament to the fact that you're massively overestimating power requirements. you'll never be using more than a third of that psu with your current rig, although to be fair you might be planning on buying a gtx480 which requires a small nuclear power station to run.
I overclock a lot and had to future proof upgrades. Then there is my 4 hds with 2 being a raid 0. I would never setup my rig that close to the limitations of my psu. His gpu and cpu alone is already 180w. Even with a 80% efficiency psu that is cutting too close for me personally and the original op will be around 235w which I wouldn't trust his no name psu if I was in his situation.
cool. i don't want to argue with you. each to their own. the tdp's for his cpu and gpu are theoretical max's though, that the cooling solution is designed to dissipate. they won't be drawing anywhere near 180w, especially if he undervolts his cpu (which i recommended). see here for an idea of actual power draw for his cpu -
http://www.lostcircuits.com/mambo//index.php?option=com_content&task=view&id=58&Itemid=42&limit=1&limitstart=6
- 68w at full load @1.35v. add about 50w for a hd 4670 (doubt it would go higher without furmark) and that's 120w max for cpu and gpu. i'm running my phenom x3 @ 1.325v on my 300w 1u psu and would happily run it as a quad core (if i could unlock the other core) and then chuck in, say, a 9800gt.
and as i said before i agree about not trusting a generic psu.
like one poster before said, the watts is relatively unimportant. with a decent for example enermax 350w psu u shouldn't run into any problems (if cpu not too much oc'ed).
my advise; new psu (and a decent one, please)
What else than CPU and GPU draws a lot of power from the PSU? I'm listening. CPU+GPU uses about half of it, and i doubt 3 HDDs and a (rarely used) DVD-Writer use the other half.
Its a good Enermax PSU that served me well for long time, and its likely to stay that way.
Your better off then the op because you cpu draws less power. Even with 80% efficiency on a 350w (you guys might have a lower rated) psu its really a 280w psu. So, your kinda in the ball park with all your hardware together. If it works for you then good. I just wouldn't used that psu on that rig. Here is a psu calculator if your interested.
http://extreme.outervision.com/PSUEngine.
That's not how PSU ratings work. That 350W is the output wattage, not input. A PSU rated for 350W that's 80% efficient will draw about 438W at max load. However, seeing as it's a no-name PSU, it is likely that that 350W rating refers to the MAX output, rather than the maximum continuous output. The continuous output will be less, and that's the number you're concerned with.
As has already been stated, though, with a modern system the total amperage on the +12V rail(s) is what you should be looking at, not necessarily the total wattage. ATI recommends 40 amps on the +12V rail(s) for a system with that card. As long as you get a quality PSU that should be more than enough; I'm currently temporarily running a 4870 (higher power consumption than the 5770) with an Antec PSU rated for only 33A total on the +12V rails with no issues whatsoever, even during OCCT's GPU stress test.
(07-04-2010, 09:44 AM)PercentSevenC Wrote: [ -> ]That's not how PSU ratings work. That 350W is the output wattage, not input. A PSU rated for 350W that's 80% efficient will draw about 438W at max load.
Yes, that's very correct. Therefore you probably misunderstood obscure's message because he is right too; A PSU that draws 350w current at 80% efficiency is practically only a 280 watt power supply (as far as the components & their power demands are concerned)
To find out the real efficiency of your PSU you would have to measure the DC output and then divide it with the AC input. So if the supply puts out 550W and taking in 647W current from wall, it has an efficiency of 85% which would be very good. The output wattage does not mean the maximum power consumption.
Anything less than 80-85% is not an acceptable efficiency ratio for a good PSU, I would throw it in the trash it it dips below 75%.
Ah, yes, if that's what he was saying, I misunderstood. My apologies.
In any case, the most important thing is to get one of the trusted brands. I, like many, many others, had to learn that the hard way. It's not worth saving a few bucks by going with a cheap PSU. It puts your whole system at risk, and when it fails early, you get to spend even more money than you would have if you'd just gotten something good in the first place.
Ok I don't wanna risk my whole system and degrade the 350w with overloaded amps. What are some good 500+ watt PSUs for under $100? I see Thermaltake is a good brand. Thanks for the awesome replies.