PC Peripherals PSU query. Is 24 pin needed?

[Fortiesboy]

This is a new system i am contemplating .

This is the quote I received

Here is the hardware spec of the system as per our telephone conversation.
The PSU is a standard ATX and NOT an ATX 2.0.

Athlon 64 PCI-Express Based
Athlon 64 ASUS PCI-Express Motherboard
Athlon 64 DualCore X2 4400 Processor
1GB DDR400 Crucial Memory
120GB SATA 7200rpm Hard Drive
DVD
128MB Radeon X300SE (PCI-Ex)
1.44MB Floppy Drive
X-Blade Black Case
Uprated 600W Twin Fan PSU
Windows XP Home - CD supplied and installed
1 Year Collect and Return Warranty
You will see that I have clarified that the PSU is NOT 24 pin.

I do not think the supplier can readily, if at all, supply a 24 pin psu.
I don't know the mobo model number (yet) but I am guessing it isn't a SLI one.
The price - In UK - is good enough for me to buy a 7800GTX ( which dealer doesn't do ) separately, but does it not need a 24 pin PSU. ?
If not, do i just replace the graphics card as normal , or is there something else I need to do because there is a 20 pin PSU in the system?

TIA

 

[Chaos]

Well it depends upon the motherboard and the graphics card you plan to plug in. Some mobos like the DFI Lanparty are totally unstable with 20 pin PSUs. Others like MSI and Asus seem to run fine. More depends upon the graphics card too. If its a 7800GTX as you say, then that PSU might make the system unstable. If its just the X300SE, then you wouldn't have too many issues.

 

[Crazy_Eddy]

These additional 4-pins in a 24-pin PSU according to the ATX 2.0 spec are used primarily to power the PCI-E bus. The PCI-E bus is designed to deliver more power (around 75 watts) than the standard AGP bus, hence the additional power requirement.

Older AGP cards that needed more power were equipped with an external power connector, since the AGP bus couldnt supply the needed power. With the shift to PCI-Express, graphics cards could make use of this additional power provided by the PCI-E bus and avoid the external connectors. However the high-end cards still surpass the power supplied by the PCI-E bus, and the 7800GTX is one such card which still has an external power connector - so I dont think you would be starved of power.