Paul wrote:
> In article <_S_zg.10219$Ca.1919@fe1.news.blueyonder.co.uk>, "Pete"
> <not@this.address> wrote:
>
>> I have just bought a Ultra Xconnect power supply 400watts to use in
>> conjunction with a AMD 3500+ and skt 939 board.
>>
>> Here it is:
>>
> http://www.ultraproducts.com/product...&productID=304
>>
>> It says it supports Pentium 4 and AMD CPUs and meets ATX version
>> 2.03 and ATX 12V version 1.2 specification.
>>
>> When I bought it I thought it was the dogs bollocks but now I see
>> motherboards with 24 pin PSU connectors and wonder what's going on.
>>
>>
>> Have I bought a lemon? Is it out of date? Has the ATX spec moved on?
>>
>> Can you plug a 20pin ATX connector from the power supply onto a 24pin
>> connector on the motherboard and then use a 4 pin lead for the
>> remaining 4 pins or would I need a convertor?
>>
>>
>> The motherboard I want to use it with has the following connectors:
>>
>> 24-pin ATX Power connector
>> 4-pin ATX 12V Power connector
>>
>> Would I need to buy extra cables / convertors to use it with this
>> board?
>>
>> Thanks
>>
>> Pete
>
> <----- ATX 2.0+ main connector -----> <--- ATX previous versions
> --->
>
> Pin Signal Color Pin Signal Color Pin Signal Color Pin
> Signal Color 1 +3.3VDC Orange 13 +3.3VDC Orange 1 +3.3VDC Orange
> 11 +3.3VDC Orange 2 +3.3VDC Orange 14 -12VDC Blue 2 +3.3VDC
> Orange 12 -12VDC Blue 3 COM Black 15 COM Black 3 COM
> Black 13 COM Black 4 +5VDC Red 16 PS_ON# Green 4
> +5VDC Red 14 PS_ON# Green 5 COM Black 17 COM Black
> 5 COM Black 15 COM Black 6 +5VDC Red 18 COM Black
> 6 +5VDC Red 16 COM Black 7 COM Black 19 COM Black
> 7 COM Black 17 COM Black 8 PWR_OK Gray 20 Reserved N/C
> 8 PWR_OK Gray 18 Reserved
> N/C (-5V)
> 9 +5VSB Purple 21 +5VDC Red 9 +5VSB Purple 19 +5VDC
> Red 10 +12V1DC Yellow 22 +5VDC Red 10 +12VDC Yellow 20
> +5VDC Red 11 +12V1DC Yellow 23 +5VDC Red
> 12 +3.3 VDC Orange 24 COM Black
>
> <--- ATX 2.0+ 12V for proc ------> <--- ATX previous versions
> --->
> Pin Signal Color Pin Signal Color Pin Signal Color Pin
> Signal Color 1 COM Black 3 +12V2DC Yellow/Black 1 COM Black
> 3 +12VDC Yellow 2 COM Black 4 +12V2DC Yellow/Black 2 COM Black
> 4 +12VDC Yellow
>
> Changes:
>
> 1) -5V removed, prev supplies probably had it. Usually not an issue.
> 2) Four addition pins on main connector. Extra +3.3V, +5V, +12V, GND
> Helps with PCI Express motherboards. For SLI boards, 24 pin
> recommended (to get two 6 amp pins to feed the two video cards via
> PCI Express slot connectors). For single video card, 20 pin is
> generally enough. 6600GT for example, draws 4 amps. Xbitlabs.com has
> measured many cards. If in doubt, do a detailed calculation.
> 3) 12V output split into two separate 12V circuits.
> No advantage to customer, due to need to allocate extra "slack"
> when buying. Perhaps intended to meet IEC60950 ? (To limit max
> power per 12V output) 12V1 feeds disks and motherboard (and video
> card) 12V2 used exclusively for processor (in your computer, that
> would be 8.24A)
>
> * 24 pin can plug to 20 pin mobo, as long as pins don't bump
> 20 pin can plug to 24 pin mobo (same pinout) - use the right holes.
> Some 24 pin are detachable, into a 20 pin part and a detached 4 pin
> part. At least one guy has managed to plug the detached 4 pin, into
> the processor Vcore input. (I haven't checked to see how hard that
> is to do.)
>
> PCI Express slots have 12V pins on them and allow up to 5 amps.
> Video cards (not overclocked) seem to be designed to draw about 4 amps
> or a tiny bit more, through the PCI Express x16 slot. The single 12V
> wire on the 20 pin connector carries at least 6 amps, so using a
> 20 pin connector on a non-SLI board seems reasonable. The fan header
> current also flows through the single 12V pin on the 20 pin connector.
>
> Main connector rated for 6 amps per pin.
> http://www.molex.com/cgi-bin/bv/mole...roductID=98716
>
> 12V processor power connect pins rated at 8 amps per pin.
> http://www.molex.com/cgi-bin/bv/mole...roductID=76873
>
> Molex disk drive connector rated at 8 amps per pin (based on assuming
> a right angle PCB mount connector, and 18 gauge wire - Amp 82181
> catalog)
>
> Enjoy your new power supply. No need for adapters.
>
> The Ultra you have selected, has 12V @ 16A. If you had an 89W AMD
> processor, that is (89W/12V)/0.90 = 8.24A. A midrange video card like
> 6600GT is 4A. That is 12.24 amps so far. A disk drive idles at 0.5A.
> A CDROM can draw 1.5A according to the rating on the label. Allocate
> 0.5A for some fans. We are now at 14.74 amps of 16A. Your new Ultra
> is suitable for a midrange gamer with minimal storage devices. More
> than 16 amps is required if your PC has more toys in it. For example,
> if you bought an ATI X1900XTX, it draws 10 amps (part through the
> PCI Express slot, part through the 2x3 PCI Express connector), and
> you would need about 12V @ 23A to have a stable computer. So, enjoy
> your new Ultra, but do not overload it.
>
> HTH,
> Paul

Thanks for the detailed reply Paul.

Just to confirm what you have said:

1. Plug the 20 pin ATX motherboard power cable into the 24pin socket on the
MB

then...

Sorry to be thick

Thanks

Pete