Hi,

This is a really basic question, but I was after some clarification of motherboard power supply connectors.
I am interested in this MB: Asus P8H67-M LX Rev3. It has a 24 pin and an 8 pin connector.
I am after a H67 SB MB with a PCI socket (to accommodate a video capture card).

I have in the past erm.. bought MB and PSU combos that had incompatible power connectors and I dont want to do it again
Are these compatible with my choice of MB?

Seasonic 400W fanless
20/24 pin
1 x 4+4pin CPU +12V
5 x 4pin Molex

Seasonic SS-560KM 560W Modular PSU
20/24 pin
1 x 4+4pin CPU +12V
5 x 4pin Molex

Seasonic S12II-380 380W
20+4pin
1 x 4pin ATX 12V
6 x 4pin Molex

Thanks,

Dave

They are likely all compatible, but I would go with either the 560KM or the X400FL because they offer an 8-pin CPU power as opposed to just a 4-pin. If you are planning on using the X400FL, make sure that there is room available in your case for the PSU to vent (upwards) as it is completely fanless.

Those are excellent units and offer great efficiency, but if you need more power (if you are running gaming graphics cards) then obviously a higher-power unit might be in order.

If you don't need that level of efficiency, there are many other great units out there. I just bought a Seasonic S12II 620W tonight. It came in quite a bit cheaper than the Gold rated units. In either case, I have had very good luck with the Seasonic X series, my main rig is powered by an X650

Good luck and post here if you have any more questions

My main PC is also powered by an X650, I really like the way that the fan hardly ever kicks in.

I'm considering something to accommodate a 4 input capture card (Picolo 2 pro) for a unit to mainly carry out a CCTV function / file server.
Its always going to be on, hence my interest in a high efficiency unit. I'm not wedded to fanless PSUs, but I really like the way that some of the seasonic PSUs fans only comes on at higher loads.
I'm considering the i3 2100 with a H67 board to take advantage of the on-CPU graphics of this SB processor and its fairly competitive in terms price vs horsepower.

On the stupid question front....
Does 1 x 4+4pin CPU +12V = an 8 pin connector?

What sort of connector is :

Seasonic 400W fanless and Seasonic SS-560KM 560W Modular PSU have:
5 x 4pin Molex (my basic maths works that out as 20 pin connector ?)

Seasonic S12II-380 380W has:
6 x 4pin Molex (24 pin connector ?)

The MB I was considering has a 24 pin (in addition to an 8 pin) connector. How does that equate to my understanding of the 20 vs 24 min power connectors provided with these PSUs?

Thanks

If you look directly on seasonic's website, it'll give you the exact cables you're going to get. The only PSU in your list that doesn't have the 8 pin CPU connector (also called EPS connector) is the 380 (only has the ATX 4 pin connector).
For the other ones :
http://www.seasonicusa.com/NEW_X-series_Fanless.htm (CPU 8/4 pin)
http://www.seasonicusa.com/NEW_X-series_560.htm (CPU 8/4 pin)

for the 380, just for reference :
http://www.seasonicusa.com/S12II-Bronze.htm
if you want to use the S12 series, get the 430, it has the 8 pin conector.

Hope that helps !

EDIT : to answer your specific questions :

Yes


The Molex connectors have nothing to do with the CPU or the motherboard connectors. Molex connectors are used to connect older CD/DVD players, older HDs (all that before SATA), some fans have a molex connector... With a recent computer, you probably won't use them if you have Sata components and use the mobo fan headers.
They look like a row of 4 wires, usually 2 black, one red, one yellow on a rectangular plug with 2 corners cut out. (http://www.google.com/images?hl=en&biw= ... 4&aql=&oq=)


same as above


20 pins is a slightly older standard than the 24 pin design. Most modern PSUs and mobos will use the 24 pins design. The extra 4 pins were added to the 20 pins design to provide extra power.

frenchie wrote

okay, I see. So the bit that details the power connector is the 20/24 pin bit: My understanding is that there is a 24pin power connector that can plug into either a 24 pin socket or a 20 pin one with overhang...

That's really helpful, thanks.

Yep, you're right.
On some connectors, the 4 pins part can be detached from the 20 pins part so it doesn't overhang.

Hi, the 4pin ATX / 8 pin EPS works the same way. First 4 pins are the ATX spec and 4 more added to get up to EPS. Often the connector splits, like the ATX one so no over hang (or interferance problems) The slots are all keyed so you shouldn't be able to plug in the wrong bit or wrong way round etc.
[I believe there maybe something in the EPS spec that dictates it be completely it's own cable, I think my PSU has the 4 pin ATX connector and a completely seperate 8 pin EPS one!]

I would think in almost all cases a 4pin ATX connector in to an 8 pin EPS socket will work just fine unless absolutely pushing the overclocking in crazy [like below ambient] teritory. For server or workstation or dual socket boards then it probably is needed.

In some cases you can also get away with a 20pin PSU in the 24 motherboard socket and have it work fine. Same as for ATX/EPS the extra pins just provide more current handling capacity.

Regards, Seb

This reply is probably too late to be of any assistance to the original poster, but I've been using the Seasonic S12II-380 380W power supply you referenced with an H67 motherboard and i7-2600 CPU and the system has been running very smoothly (and quietly -- at least by my standards). My motherboard* also has an 8-pin connector for the CPU. The 4-pin ATX plug from the PSU will connect to the 8-pin connector on the MB.

It seems strange that these desktop boards have ESP12V connectors for the CPU. Maybe because the retail PSU market is dominated by ridiculously oversized units?

To put things in perspective, I recently helped someone setup a couple of new Lenovo Thinkstations that were equipped with previous generation i7-8xx CPUs. They had two 1-terabyte hard drives, a Blue-ray burner, and a discrete graphics card. The power supplies were 260W LiteOn-branded units.

SPCR's PSU review section is one of few places that offers sensible information about PC power requirements.

* A Gigabyte mATX board (GA-H67MA-UD2H-B3)