TSGL: Power with AGP or PCI-e

[John S]

Bo wrote:
> >> Of most interest right now is a GeForce
> 7600GS or 7600GT card.
>
> These cards are available as both AGP and PCIe versions (my MB supports
> only AGP). My question now is if anyone knows if AGP configuration
> require more or less from the PSU? Or is the graphical bus irrelevant of
> how much power the card will draw from the system? <<
>   
Bo,
Your present ATI-9800 card draws 42Watts. The general limitation current 
draw from an AGP3.0 standard (AGP8xx) slot is 40 to 42Watts.  As you can 
see, your present card is maxing out what your AGP slot can deliver as 
it is.

The nVidia 7600GS card draws 27Watts and the 7600GT draws 36Watts.  Due 
to more efficient architecture these days in vid cards more can be done 
with less power consumption.  Similarly, this advancement is occurring 
with RAM modules and CPUs.
Therefore, you will be fine with fitting either the GS or GT cards to 
your AGP slot even with their self contained cooling fan(s).

I have one 7600GS (AGP8x) card fitted to one of my machines and can 
vouch that it is an excellent bit of gear.

Of course you could fit a card to your AGP slot that drew much more that 
40Watts.  Such cards should already have an additional socket to be able 
to receive additional power from an available power chord with a small 
Molex plug coming from your PSU for that purpose.  I suspect from 
reading your post that you may not have a spare power chord available.  
Anyway, I would not suggest the use of power splitter cables with a 
250Watt PSU as it is likely to be supplying near all the current it can 
with your present configuration.

The PCI-Express Standard allows a maximum of 75Watts to graphics cards 
through PCI-E slots.  Hence, MBs with such multiple PCI-E slots will 
supply power to the vast majority of mid to high-end vid cards (even 
when more than one such card is fitted) without the requirement of 
additional power supply.  Naturally, boxes with such MBs will 
undoubtedly be (or should be) fitted with substantial PSUs (480W min ??) 
wherein a lot more power is required for adequate overall cooling 
purposes as well.

Cheers... ~ John S.