DirectX12 + GTS 250 PhysX card

ALL DX9/10 GPUs (including onboard and mobile units) have become EOL (End of Life) as of 4/2014 and thus will NOT receive any additional driver support/updates after that date. This includes the 6000,7000,8000,9000,100,200,300, and some lower-end 400 series. Thus semi-modern drivers for the gts460's will not support the GTS250. (Not to mention you cannot currently "mix" differing generation GPUs within Win10 currently)

Do I need to replace the PhysX GTS 250 with a Fermi or later card to keep my SLI cards using DX12?

You need to replace it with another "Fermi" genersation GPU if you wish to continue using a dedicated PPU. Although; on that note pretty much "ANY" single, modern, "GTX" class card would outperform all three of the GPUs you have installed combined.

Hey man. Thanks for the thorough reply. The 2 GTX 460s are GS GLH. versions. Was hoping for maybe just a low end to run PhysX. I'm not looking to spend a lot atm. I see much better frame rates with the latest driver (DX12) than the old one. Thank you man.

Hello to all. I couldn't find any info about my problem, so here I am. My graphic setup is 2x GTX 460 SLI + a GTS 250 for PhysX. DirectX 12 API is active on the SLI cards with driver 355.82, but it stops the 250 from working. If I uninstall and reinstall the 250 in Device Manager, Windows 10 reverts the driver back to an earlier version where the GTX 460s are running DirextX 11.1, driver 341.81. Can Windows run the SLI cards as DirectX 12 capable cards while still using the non DX12 capable GTS 250 just for PhysX? Or am I naive in thinking both APIs can function at the same time? (*Edit* : in driver 341.81 the 460s run API 11.1 and the 250 runs API 10.0, so it seems possible) Do I need to replace the PhysX GTS 250 with a Fermi or later card to keep my SLI cards using DX12? Thanks for any clarification and help.