s12-330 enough power for this build? how about SLI?

[betty]

Hello All,

I know that there are plenty of threads in these forums about not needing that high of wattage for system builds these days. Just the same, I see that the reccomendation is that people get the s12-430 for their systems.

I have an s12-330 that I recently purchased for an older computer. Now that older computer has died (the mobo), and I am looking into the following build, I am a little bit worried that the s12-330 is not enough.

MSI NEO F k8 Mobo
Athlon X2 3800+ (dual core)
Asus 7800gtx 256mb
1 sata samsung hard drive
1 7200.7 pata hard drive
1 dvd burner
1 additional usb add on card
3 120mm fan's.

1. Given the power requirements of the videocard and the processor, should I be worried about anything using the s12-330? I think it will be fine, but wanted to confirm with you. (I don't want to go out and buy another power supply).

2. Finally, I guess I can never use SLI with this power supply, or can I? I wanted to buy an SLI board for possible future expansion - and I know that many vid cards come with additional power cables.

Can the s12-330 support the above set up but in SLI with TWO 7800gtx cards with the use of aftermarket PCI-E power connectors?

Thanks!
betty

[stromgald]

I think a 330W could handle the system you have listed there. However, I don't think it will handle a SLI setup with two 7800GTXs. The power consumption of high end graphics cards are up in the 50W range, and two of them combined with a high end CPU with some miscellaneous other things may be too much for a 330W PSU. You might be able to get away with the 380W version, but I'd feel safer recommending 430W for two 7800GTXs in SLI.

IMO, the main reason people toss out the 430W version so much is because it came out first (the 330W and 380W version showed up later at newegg at least), and was reviewed by SPCR. It also future proofs the system pretty well because it'd be enough to support SLI.

[betty]

mmm. Good to know.

So I *definitely* won't have a problem with the non-SLI setup I have described above right?

I think that is what I'll do then, and instead of going for an SLI in the future, just invest some extra money into getting the 512mb 7800gtx despite the ridiculous cost. I don't like to upgrade my system often - i've kept my last computer since 1998.

Thanks again,
betty

[betty]

According to Tom's hardware, the 7800gtx pulls 250W of power during gameplay!

Given this, will the s12-330 (which I already have) really be enough for that kind of a graphics card, in addition to a dual core athlon 64, 2 hd's, 1 usb add on card, ram, system fans, and dvd-rw drive? (NON-SLI) Or do I really need to go out and purchase a new psu?

Can someone else please weigh in?

Many thanks!!!
betty

[egale]

I don't think that PSU has a PCI-E connector. The 430 unit has one I believe and the 500 unit has two.

[stromgald]

I don't think that PSU has a PCI-E connector. The 430 unit has one I believe and the 500 unit has two.

Isn't that what a molex to PCIe adapter is for?

betty, if you're referring to this article on THG, then I think you should notice that the ~265W power consumption while gaming is the power consumption of a whole system not just the graphics card. The numbers quoted by nVidia (120W peak, and at least a 350W PSU w/22A on the 12V line) are probably more accurate.

Although the Seasonic 330W has only 22A split between its 12V lines (8A, and 14A), I wouldn't be too worried. Good manufacturers always err on the conservative side to avoid complaints/lawsuits. The Seasoinc S12-330W could probably provide 23A on its 12V line, and the 7800GTX-512MB from nVidia probably actually consumes 5-10% less power than advertised.

Maybe one of the reviewers with more expertise can weigh in on this and the molex to PCIe adapter issue . . .

[betty]

Hmm. Ok thanks. That helps, I'm *less* worried. Anyone else?

Thanks again!
betty

[hightower]

i would not go with a psu less than s12-500 (maybe enermax liberty 400w). it's only the 600w s12 that is sli certified. there is *probably* a reason why they don't put 2 x pci-e connectors on their 330w but they do on their 500 and 600w

[~El~Jefe~]

no reason not to go with a 430 seasonic. has the best efficiency out there just about and can take a heavy load from sli.

500+ is really just about the same effect. I dislike such options as a rule, as do most spcr types. they have much louder starting/idle fan noises.

[Bobthebuilder]

Amps X Volts = Wattage


Which means your +12V line has a very low amperage (Is that english? lol not my native language)

When you're using that kinda hardware you will need more power I can assure you that

[hightower]

2 molex = 1 pci-e. So with a S12 430, you are going to take away 4 molex to run 7800gtx in SLI. Imho, that's just bull to recommend, even if it's possible. There is a reason they made those pci-e plugs on their higher power versions. And lets be real: If you're serious about silence, you don't go SLI.

[stromgald]

2 molex = 1 pci-e. So with a S12 430, you are going to take away 4 molex to run 7800gtx in SLI. Imho, that's just bull to recommend, even if it's possible. There is a reason they made those pci-e plugs on their higher power versions. And lets be real: If you're serious about silence, you don't go SLI.

Where do you get that 2 molex = 1 pci-e connector? I've seen adapters that use 2 molex connectors, and I've seen adapters that use 1. PCIe power connectors do not deliver any more power than a regular molex. It draws from the same rails as the other molex connectors on the power supply. Its modified so it has 2 12V wires, and 3 ground wires rather than the 12V, ground, ground, 5V of molex connectors, but unless you're worried that the 12V wire of the molex will burn out from the load, there's no difference. Having a dedicated line for PCIe does limit the interference of having other components connected to the line, but that is rather insignificant, you could just use a line from the PSU and leave that other molex on the same line unusued.

The reason I, and many others on SPCR, would recommend 430W for SLI, is that independent testing by xbitlabs, and at SPCR indicate that SLI can be run on 430W. The main reason that you see manufacturers specifying 500W+ is because in certain manufacturing processes, there is margin heaped upon margin with more margin stacked on top of that. As a result, the requirements get more and more inflated. Getting a 500W PSU for SLI is unnecessary unless you're using lots of PCI cards that uses the 12V rail.

Amps X Volts = Wattage

Which means your +12V line has a very low amperage (Is that english? lol not my native language)

When you're using that kinda hardware you will need more power I can assure you that Wink

http://www.silentpcreview.com/article265-page1.html
http://www.xbitlabs.com/articles/video/ ... 512_5.html
You can believe what you want, but testing seems to indicate otherwise.

[hightower]

I have not found an adapter that only uses 1 molex, however if you say they excist, I believe you. The adapter that came with my leadtek 7800GT used 2 molex. However, why use an adapter (or two) when there are units who have these pci-e plugs - native? I personally do not like the idea of adapters - I prefer native support. The 430 might be quieter than the 500, but not by much compared to the noise generated by 2 graphics cards against 1.

[stromgald]

My dream machine would have two of those ASUS passive 7800GTs in SLI mode with a Nexus fan blowing over them. The top one's movable radiator would hang over the CPU too for more cooling. All of it would be wrapped in a P180 to keep it quiet. I would get a 430W for that, but I tend to run 4+ hard drives and that tends to use up all the molex connectors, so I'd get a 500W S12 anyways, but not for the wattage.

Of course if you have fanned GPUs, your statement would hold true. The extra graphics card would probably drown out any difference between the 430W and 500W. The cost is the principal driving factor for me since I don't think the noise between the 430W and 500W Seasonic S12s is significant.

[betty]

Hold on a second!

Let's say I DON"T want to run SLI. I want to run a SINGLE 7800GTX, x2 athlon processor, etc. with an s12-330 (which I already OWN).

This is fine, is'nt it?

Thanks!!
betty

[~El~Jefe~]

2 molex = 1 pci-e. So with a S12 430, you are going to take away 4 molex to run 7800gtx in SLI. Imho, that's just bull to recommend, even if it's possible. There is a reason they made those pci-e plugs on their higher power versions. And lets be real: If you're serious about silence, you don't go SLI.

thou art: pwnd

[~El~Jefe~]

Hold on a second!

Let's say I DON"T want to run SLI. I want to run a SINGLE 7800GTX, x2 athlon processor, etc. with an s12-330 (which I already OWN).

This is fine, is'nt it?

Thanks!!
betty

what's with the 330 desire? spend a few bux more and get a 430. it has the same noise levels. It is possible the psu fried the mobo isnt it?

gtx buyers should not be chincy! unless you have it already then you are STILL in the clear. a x2 3800 is low power req. by the way. the 4800 uses a bit more on load though. gtx uses gets considerably hotter than a single 7800GT, but it still beats a x1800 XT wattage wise.

[qviri]

what's with the 330 desire? spend a few bux more and get a 430. it has the same noise levels.

I have an s12-330 that I recently purchased for an older computer.

[MikeC]

betty, if you're referring to this article on THG, then I think you should notice that the ~265W power consumption while gaming is the power consumption of a whole system not just the graphics card. The numbers quoted by nVidia (120W peak, and at least a 350W PSU w/22A on the 12V line) are probably more accurate.

Although the Seasonic 330W has only 22A split between its 12V lines (8A, and 14A), I wouldn't be too worried. Good manufacturers always err on the conservative side to avoid complaints/lawsuits. The Seasoinc S12-330W could probably provide 23A on its 12V line, and the 7800GTX-512MB from nVidia probably actually consumes 5-10% less power than advertised.

Maybe one of the reviewers with more expertise can weigh in on this and the molex to PCIe adapter issue . . .

One of the huge problems with the infor on the THG article cited is that "the ~265W power consumption while gaming" is not clear enough. OK, so this is for the WHOLE system, but did they measure AC power input at the outlet or did they measure DC output from the power supply??

Not knowing this, the info is just about useless.

But getting back to Betty's question.... about whether the S12-330 is enough for a "SINGLE 7800GTX, x2 athlon processor" system....

Probably.

I would trust x-bit labs measurement of 107.8W for the 7800GTX-512 much more than anything from THG (they are so un-transparent!) But 256mb less might mean just 100W...

So then add 65W for the CPU -- data from xbit labs again
Maybe another 60W for motherboard, memory + drives (incld optical)

Call it 225W total on the 12V line.

Assuming you have low 3.3V and 5V requirements (typical), the Seasonic can give you a max of 22A on the 12V line -- this is 264W. It should be fine.

What's the worst case scenario? It's not quite stable enough when you push everything to the max silultaneously... so you get a bigger PSU and sell of the 330... or don't push everything full tilt simultaneously?!

[~El~Jefe~]

bah i know that.

i said that because well, the s12 430 on line is rather cheap.

check out how much a x2 and 7800 GTX is !!

she can get a new psu.