SLI GTX 460 with GT 240 Physx.. help

No , I would not. The cards have completely different architectures but have similar performance. PhysX uses the cuda cores your 8800 has 112, the gt 240 has 96.
The gt240 at 70 bucks is not a bad deal, they are on the 40nm process. If you had another use for your 8800 maybe, but not necessary , its not a upgrade.

damn thats odd, i just used the Benchmark on the Batman AA game with SLI on and the 8800 GTS dedicated to Physx i get an Average of 65 FPS, with the SLI on with out using the 8800 GTS as physx 115 FPS.... wtf lol i think the old GPU or DDR3 on the 8800 GTS is slowing down my GTX 460 SLI. BTW i never knew the 8800 GTS was able to run Cuda, according to the GPU-Z it doesnt..

I believe CUDA is based on nvidia's stream prossesor technology, now called ''CUDA CORES''. If I'm right even 8400GS' are able to run CUDA (of course, VERY, VERY slowly)

Have you set the 8800GTS as a PhysX card?

+1 ^ mousemonkey

set the 8800 GTS as your dedicated physx card in the nvidia setup settings!! then run your tests again!!

++++++++1^^^^^^^^

its been set as the dedicated card   i take it something is wrong then, i should sell the 8800GTS and get the GT 240

Yes

You FPS are going to be lower enabling physX, it takes down the fps quite a bit.
This is using a gtx 260 as a dedicated physX card.
http://www.hitechlegion.com/reviews/gaming-software/526...

Right right bud i understand that, what i cannot understand is how in the world i get 115 FPS with Phsyx on only with GTX 460 SLI with out the 8800 GTS as dedicated card... and get 63 FPS with SLI on Physx on with the 8800 GTS set as dedicated card, i dont wanna sound like im bitching cause im happy i get 63 FPS because its playable but this doesnt make sense you know  

hmmm

Bumping threads is just likely to get them locked.  

Dedicating a card for physx is typically a waste of time and isn't worth it. If you need the bump in performance the nuke the shader on one or both of your cards. You can have differential clocks and it wont hurt performance. Having a dedicated card only increases power consumption and more lag on the cpu. You should just stick with what you have and don't spend a dime on the gt240.