X58 and PCI-e lanes and PhysX

JDT_JDT

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Feb 12, 2010
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Hi, hope you knowledgeable hardware guys can help me.

I'm thinking of getting a Gigabyte GA-X58A-UD3R, and eventually pairing this with an SLI set up of Fermis when they come out. At the moment I have a 8800GT that I intend to use in the mean time.

I have heard that any 8000 GeForce Series can be used as a dedicated PhysX processing board, so it might be worth hanging on to this board anyway. My question is the following:

The X58 has 36 PCIe lanes. It seems sensible to have two Fermi cards eventually using 2x16 lanes, which the chipset supports. However, if I want to use the 8800GT as a PhysX accelerator too, does that mean I need to split it to 1x16 lane and 2x8 lanes? Or is it possible to have my SLI cards using 2x16 lanes, and leave the 8800GT the 4 extra?

Secondly, I don't really know how cards fit these days - would it be possible to have 2x fermi cards, a 8800GT and a soundblaster PCI card in this system? I mean, would it it on the motherboard? If not, I guess I have to make a choice between PhysX and a dedicated sound card.
 
Quick answer:
Buy that motherboard assuming it has THREE of the full-size PCIe for your graphics cards then simply experiment.

Long answer:
Your setup would likely go something like->
1) 2xNVidia Fermi's (joined together with the SLI link)'
2) 8800GT (by itself)
3) audio card (PCIe or PCI) *Make sure there is room!

If you get two pretty good Fermi cards then you might find the 8800GT contributes very little and in same cases may make things worse. You'll need to experiment on your own. Keep in mind that often things change for the better with driver updates.

The 8800GT will also add heat and noise while doing very little most of the time.

Now here's a big one:
NVidia just released the "Optimus" setup for laptops. That is two graphics chips on the same laptop. That's not new but what is new is that they can turn whichever chip is not needed off COMPLETELY.

I bring this up because this type of technology may not be too far behind for the desktop. It only makes sense that it's coming since the technology is the same.

This technology requires a compatible motherboard (none exist yet) and compatible graphics cards. It would be AWESOME if this technology was announced in March but we'll have to wait and see.

An X58/920 setup could idle at about 100 Watts (rough guess). I'm betting a high-end Fermi would idle at around 40 Watts. Two Fermi's is 80 Watts. So if they aren't turned off then your system may idle at 180Watts instead of 100Watts.

My advice is to not buy anything until Fermi is released.