[Smartflight]

It's usually on the PSU, but in my case, it's not written.

Instead, we have this information available:

Quantum Power Supply
Model - SMPS P-IV 300k
AC INPUT 230/115VAC 50/60GHZ 2.5/5A
Fuse Rating: F5A 250VAC

I am looking to buy a new GPU, but if I need a new PSU to supply a hungry GPU, it's gonna be problem. Can anyone figure out the power in Watts of the PSU I have right now?

[waldojim]

Smartflight, on 23 March 2012 - 01:31 AM, said:

It's usually on the PSU, but in my case, it's not written.

Instead, we have this information available:

Quantum Power Supply
Model - SMPS P-IV 300k
AC INPUT 230/115VAC 50/60GHZ 2.5/5A
Fuse Rating: F5A 250VAC

I am looking to buy a new GPU, but if I need a new PSU to supply a hungry GPU, it's gonna be problem. Can anyone figure out the power in Watts of the PSU I have right now?

That model number alone pretty well tells you it is a 300 watt power supply. The problem here, is that I doubt you could ever coax it into delivering 300 watts. More likely, it will cook itself if you try to draw more than 200W. If you are looking into a new dedicated video card, budget in a power supply as well. An Antec Earthwatts 380 can usually be found pretty cheap, and will easily tackle up to an Nvidia 550ti or AMD 7770. For video cards more powerful, look into a decent 500 watt power supply, such as the Antec High current gamer, Silverstone ES series, Corsair TX series, OCZ ZT series or similar.

[LiveBrianD]

I've never heard of that power supply. I agree with waldojim here. Another good budget option to look into, which I have, is the Seasonic S12II 520W.

[Smartflight]

waldojim, on 23 March 2012 - 02:33 AM, said:

That model number alone pretty well tells you it is a 300 watt power supply. The problem here, is that I doubt you could ever coax it into delivering 300 watts. More likely, it will cook itself if you try to draw more than 200W. If you are looking into a new dedicated video card, budget in a power supply as well. An Antec Earthwatts 380 can usually be found pretty cheap, and will easily tackle up to an Nvidia 550ti or AMD 7770. For video cards more powerful, look into a decent 500 watt power supply, such as the Antec High current gamer, Silverstone ES series, Corsair TX series, OCZ ZT series or similar.

Right. I'm looking to buy AMD HD6750 (other options are HD5670, and HD6670, both 1 GB GDDR5) and the website says the power supply required is 450W. But there's no way in hell the GPU is going to need that much, is it? I think I'll pair that with this Antec, unless there is something wrong here I don't see.

LiveBrianD, on 23 March 2012 - 02:29 PM, said:

I've never heard of that power supply. I agree with waldojim here. Another good budget option to look into, which I have, is the Seasonic S12II 520W.

Trust me, neither have I. Got this build from a family member some time back, thought I should upgrade it.
The Season S12II-520 is going to cost me a bit too much, but do you recommend it over the Antec I'm considering, if I can pool in that much money. It's unlikely but just in case.

This post has been edited by Smartflight: 23 March 2012 - 11:25 PM

[waldojim]

Smartflight, on 23 March 2012 - 11:15 PM, said:

waldojim, on 23 March 2012 - 02:33 AM, said:

That model number alone pretty well tells you it is a 300 watt power supply. The problem here, is that I doubt you could ever coax it into delivering 300 watts. More likely, it will cook itself if you try to draw more than 200W. If you are looking into a new dedicated video card, budget in a power supply as well. An Antec Earthwatts 380 can usually be found pretty cheap, and will easily tackle up to an Nvidia 550ti or AMD 7770. For video cards more powerful, look into a decent 500 watt power supply, such as the Antec High current gamer, Silverstone ES series, Corsair TX series, OCZ ZT series or similar.

Right. I'm looking to buy AMD HD6750 (other options are HD5670, and HD6670, both 1 GB GDDR5) and the website says the power supply required is 450W. But there's no way in hell the GPU is going to need that much, is it? I think I'll pair that with this Antec, unless there is something wrong here I don't see.

LiveBrianD, on 23 March 2012 - 02:29 PM, said:

I've never heard of that power supply. I agree with waldojim here. Another good budget option to look into, which I have, is the Seasonic S12II 520W.

Trust me, neither have I. Got this build from a family member some time back, thought I should upgrade it.
The Season S12II-520 is going to cost me a bit too much, but do you recommend it over the Antec I'm considering, if I can pool in that much money. It's unlikely but just in case.

I run a 5770, which btw, is the exact same thing as the 6770, on an Antec 380W. The reason they suggest 450watt power supplies, is that they are trying to make darned sure that the cheap generic power supplies that most people have, don't blow up. That Antec you listed might do, but I would actually recommend the EarthWatts line, of High Current line long before most of their other products.

From that site you mentioned, and at roughly the price of the Antec you listed, you may be better off with this Seasonic instead. I wouldn't call these the best line ever out of them. But for a cheap PSU that will do exactly what you need, that should work out well.

[coastie65]

Hi and welcome to the forums. Judging from your budget, I think you would do well with this one : http://www.flipkart....3b-31140bff3f67 There is plenty on the rails and Corsair is a reliable Power Supply ( I have Corsair in all of my Desktops ). You also have plenty on the rails with that one.

This post has been edited by coastie65: 24 March 2012 - 09:10 AM

[Smartflight]

Those two are indeed budget options, thank you. I looked at the Corsair before but wasn't sure. What's with these rails, though? I mean, people seem to say you need a particular voltage rail to power the GPU or something?

[LiveBrianD]

A power supply has a few "rails". How do I explain it.... they're basically different voltage lines I guess, some have the same voltage, some different. Modern power supplies have these:
+3.3V, +5V, +12V, -12V, +5VSB. 3.3V and 5V aren't used for a whole lot, 5V does things like USB and some hard drive and optical drive stuff, 3.3V does memory, and 12V does the major stuff, like the CPU and GPU (you might have more than one 12V rail). -12V isn't used for much of anything nowadays. Good power supplies can usually provide the majority of their wattage on the 12V rail(s). In a lot of cases, the power supply's 12V rails might add up to, say, 500W, but it can only provide 400W total (for instance, the invididual rails can do 250W each, but you can't load both of them at once). Or, for instance (and this is even more common), the power supply's rails might add up to, say, 610W, but the unit is 520W (my seasonic is exactly that way - 480W on the 12V rail and 130W on the 3.3V and 5V rails, but I can't load all of the rails to the max at once). Some cheap units are heavy on the 3.3V and 5V rails, but not so much on the 12V rail, which won't help you nowadays. Earlier computers, like the Pentium 4 PGA423 and back ones, were heavy on the 3.3V and 5V rails, while the newer ones like the Pentium 4 PGA478 and up are heavy on the 12V rail instead.

[Smartflight]

Thank you. Very good explanation there!