Seasonic S12 430w or 500w

[rouseindahouse]

Well, I'd initially planned on getting a Q-Technology 400w for my existing PC seeing as they'd been incredibly quiet but after reading around on here I've been swayed by the Seasonic.

I know these aren't the support forums but I was wondering if you could help me out with a few things.

My PC at the moment runs fine on a cheap 400w psu but I'm planning on upgrading. I'll be getting an X2 (4400+ ish) and a 7800GT. I didn't think it'd be too much of a problem to get the 430w as technically it should be able to cope but on the feature list of the 500w you've got.

Supports Dual CPU motherboard 8-pin 12V cable

Does this mean that the 430w S12 wouldn't be able to cope and I'll have to go to the 500w?

[RV8C]

S12-430 does not have a PCIe power adaptor. If you want to run a 7800GT, you'll need to use an adaptor that takes up 2 molex plugs. Th S12-500 has 2 PCIe connectors (it's rated for SLI by nVidia). So it depends on which way you want to go. I've got both a 430 and the 500 and both are great.

Cheers

[Tibors]

Supports Dual CPU motherboard 8-pin 12V cable

This has nothing to do with dual core CPU's, which are two cores in a single CPU. It is a connector needed for motherboards with have two sockets for one CPU each. These are server motherboards.

[rouseindahouse]

Ahh, thanks for the input guys. Totally forgot about actual dual core motherboards and thanks for the help about the 7800gt. Is there any chance of me going over the 430w limit with the following set up?

X2 3800+ clocked to 2.5ghz
2gb pc3200 ram
2x SATA hdd
2x DVD Drive
1x 7800gt
TVTuner and Wireless PCI Cards
2x fans

[raziell]

it will hold like king...
my rig was in the begining on
antec 350W and work great...
so don't worry.

[Elixer]

Is there any chance of me going over the 430w limit with the following set up?

No. I'd be very suprised if you broke 300, or even 250.

[AZBrandon]

Is there any chance of me going over the 430w limit with the following set up?

No. I'd be very suprised if you broke 300, or even 250.

Indeed. My 3700+, o/c'd 5% at stock voltage with a 7800GT and 4 SATA hard drives peaks at 165-170 watts according to my Kill-A-Watt. Based on the approximate 80% efficiency of my S12-600, I'm using, oh maybe 130 to 135 watts or so. Good thing I went all out for the 600 watter!

[TomZ]

If you can afford it, you should go with the S12-500. The 500W and 600W are a newer design than the 340W, and are quieter and more efficient. Also, buying more power capacity than you need is smart because if one of the voltage rails does get overloaded occasionally, this can cause random lockups. Also the 500W is more likely to meet the power requirements of your next upgrade or build.

[Tibors]

Sorry TomZ,
but according to the SPCR reviews about everything you say is wrong.
Check the numbers here:
Corrected Efficiency Results for Recommended PSUs
Seasonic S12-500 & S12-600 Power Supplies
Seasonic S12-430: Beyond the Super Tornado
You can ignore everything measured at an output higher than 200W, since that will never be reached in the proposed system.

For noise the 500 & 600 are 1 dBA louder than the 430 on two measurement points. But the human brain can't distinguish a difference of only 1 dBA......

For efficiency the 430 scores worse than the 500 & 600 at only one measurement point by a whopping 0.2%. At all other points it scores better. Differences of 1% are well within the margin for error and the tolerence for individual sample variance, so this difference between the PSU is again negligable.

The chance of occasionally overloading a rail in the 430 is not bigger than in the 500 & 600. Only the 12V lines differ. The smallest is 168W. Since the peak load of the whole system is hardly going to cross that line........

Power consumption of processors is going down, not up.
_________________

So the only deciding factors that stay, are price and PCI-E connectors.

[TooNice]

S12-430 does not have a PCIe power adaptor. If you want to run a 7800GT, you'll need to use an adaptor that takes up 2 molex plugs.

Is the adaptor provided with the PSU? I didn't know that PCIe requires its own power connector (never owned a PCIe system before). Are those adaptors bulky?

I am also unsure about the 430W vs 500W decision.

My next system is going to be based on the following:

- AMD Opteron 165 (dual core, and it will be overclocked)
- Radeon X1800XT
- 4 HD including one 10k RPM Raptor.

I guess those are the main power drainers. There will be fans, high end sound card etc. etc.

I suspect that the 430W is enough, and I probably won't go crossfire in the near future. The cost difference is pretty significant:
- £87.53 for the 500W : 45% more expensive than the 430W!
- £60.50 for the 430W : 43% more expensive than the 380W!
- £42.29 for the 380W

Actually, even the 430W is kinda expensive when compared to the 380W. But I do keep my PC on for long hours (many days at a time), so I don't want the PSU to choke at any point. There is also a 330W but its only like 20% cheaper than the 380W and definitely not on my list of considerations.

[TooNice]

I would like to add that the 600W is a mere 10% more expensive than the 500W version.

I have also heard from another forum that the 500W version has a better fan controller (= quieter). Can anyone here verify this?

[Deathlife]

the human brain can't distinguish a difference of only 1 dBA......

That's not true. The dB scale (and in consencuence de A ponderated scale) is "designed" if you like to adapt the human ear sensitivity. Usually, at larger intensities, harder it is to identify a fractional increase or decrase in intensity. Since de dB(A) scale corrects both the logarithmic behaviour and weighs out the frequency sensitivity, one should tell de difference between something from 40 to 41dB(a).
However, the A scale is used for an average person, and anyway, loudness will always be subjetive and depends on so many factors (where is the source located, its orientation etc)

[TomZ]

The 600W is quieter than the 500W by a 2-4 dBA across the entire load range.

Despite what Tibors said, I think the 500W and 600W supplies have been upgraded since the SPCR review. I read elsewhere that they have improved fan controllers that make the supplies quieter than the 430W.

Although the 500W met my system power requirements, I decided on the 600W because it was just a few dollars more and is quieter than the 500W. I was building a quiet, but high-performance PC. Having more power is only potentially harmful to your wallet, and might be useful for future upgrades. The supply is the same size, is very quiet. I also think that running at lower than its capacity, rather than near its capacity, will extend the life of the supply.

Tibor said, that the 12V is mainly where the difference is between 430W and 500W+ - and I agree. If you look at the specifications for new, high-end motherboards, they need high current on the 12V2 line. For example, Intel's reference platform for the 975X chipset needs 16A continuous and 19A peak. That removes most lower-power supplies from consideration, including the S12-430 (15A rating).

I also disagree with what was stated by Tibors, that power consumption is decreasing. I upgrade every ~2-3 years, and my power requirements climb each time. Power efficiency increases, perhaps, but operating frequency increases, cache sizes and speed increase, DRAM speed and size increase, number of cores increases, and GPUs require more and more power. While it is possible to go to a lower-power rig, if you want performance, the cost is power. This is a fact.

[StarfishChris]

I think the 500W and 600W supplies have been upgraded since the SPCR review. I read elsewhere that they have improved fan controllers that make the supplies quieter than the 430W.

Can you give us a link? It would be interesting to see what (if?) they changed anything.

For example, Intel's reference platform for the 975X chipset needs 16A continuous and 19A peak.

Is that with all PCI(-E) slots and CPU drawing maximum power? That's the only way it will need 192W continuous...

I also disagree with what was stated by Tibors, that power consumption is decreasing. I upgrade every ~2-3 years, and my power requirements climb each time. Power efficiency increases, perhaps, but operating frequency increases, cache sizes and speed increase, DRAM speed and size increase, number of cores increases, and GPUs require more and more power. While it is possible to go to a lower-power rig, if you want performance, the cost is power. This is a fact.

It may be true for GPUs, but CPU manufacturers are aware that 120W-scoffing beasts are not the way forward. The trend is towards lower frequencies (compare the 3+GHz of Prescott and the 2GHz of Dothan) and multiple cores, providing more performance-per-watt than before. Personally I cannot wait for a similar thing to happen in the graphics world - that doesn't involve two cards with a circuit board between them.

[TomZ]

Can you give us a link? It would be interesting to see what (if?) they changed anything.

I can't recall where I got that information, sorry. I'll look some more and see if I can find that and give you a link.

Is that with all PCI(-E) slots and CPU drawing maximum power?

I don't know how Intel rates this. Here is the page with the information:

http://support.intel.com/support/mother ... 022070.htm

(The Pentium 940, 950 and 955EE processors are Platform Compatibility Guide 05B.)

[Tibors]

the human brain can't distinguish a difference of only 1 dBA......

That's not true.

I suppose all the people who have said this on SPCR dureing the last few years are quite dump. And the person who put the following text into Wikipedia, didn't know what he was writing about either.

Under controlled conditions, in an acoustical laboratory, the trained healthy human ear is able to discern changes in sound levels of 1 dB, when exposed to steady, single frequency ("pure tone") signals in the mid-frequency range. It is widely accepted that the average healthy ear, however, can barely perceive noise level changes of 3 dB.

So, yes your description of how the decibel scale was designed is true. Except you forgot the part about "single frequency signals". And I forgot to mention that a PSU fan makes a broadband noise. At least a good one does.

(I know wikipedia is not an authorative source, but I can't be bothered to find something beter at the moment.)

[Tibors]

Very interesting, but where did you find the 600 watt version is 2-4db quieter on average than the 500 watt version?

I can't recall where I got that information, sorry. I'll look some more and see if I can find that and give you a link.

Seasonic sent me dbA vs. load graphs for the two models.

Either you have trouble with your short term memory or one of them is not true.

[TomZ]

Either you have trouble with your short term memory or one of them is not true.

That was a copy and paste error - sorry! I've already fixed that post.