SLI and PhysX settings question

Here are the specs on my laptop:

Dell XPS 1730M
Core 2 Duo Extreme 2.8 ghz
4 GB RAM
GeForce 8800GTX w/SLI
17" 1080i monitor, though I normally connect to a 22" 1080i monitor
Ageia PhysX chip
Windows 7 64-bit

I have two questions.

1) Given that Nvidia bought out Ageia, does the Ageia chip actually do anything now? Modern Nvidia drivers run PhysX, so....

2) When I turn on SLI I have the option of running PhysX on GPU1, GPU2, or the CPU. Which option is best? If I choose to run PhysX on one of the GPUs, does that GPU get taken out of the equation for graphics processing and become dedicated only for PhysX processing?


I've been playing The Witcher Enhanced Edition, which definitely uses SLI and PhysX.

75 views and nada?

no - it will not be a "dedicated" PhySx card - it's the same as having one GPU and choosing to enable PhysX on it - you just have to choose which one you want to handle the extra load. I'd go with GPU2.

*actually I'd say screw PhysX and play without it, it's never been something I needed, but I've been called weird before too...... :/

PhysX makes knocking down walls and explosions look cool.

1). Yes, the Ageia card is now useless.

2). If you choose to run PhysX on GPU2, it will slow down its performance a bit, but not substantially. GPUs are very very potent physics processors. Physics processing is a part of the die that is specifically intended for that purpose, apart from graphics processing (mostly) Turning it on will drop performance, but not drastically.

What about running PhysX on the CPU? Unwise?

Extremely. 12 chars.

run it on the cpu and you might as well buy an AMD card, since that's what they have to do when PhysX is enabled.... and it is a big FPS hit too. :/