Would two GTS 450 1.5GB cards in SLI mode be better than GTX 750 1GB?

[Faizan_15]

System specs:
Intel core2 quad Q9550 4-core processor 2.83GHz
Dell inc.oc27vv Motherboard
6GB DDR3 RAM
250GB HDD Drive
Nvidia GeForce GTS 450 1.5GB

My question is, if I purchase another GTS 450 1.5GB card and SLI it, will I have better performance than buying a single GTX 750 1GB? Or should I just buy the 750? And if I should buy the 750, what would be the pros and cons of using the 450 as a dedicated PhysX card? Thanks for the input!

 

[geofelt]

Find your parts in used condition on ebay.
Then filter on completed auctions,
In green you will see what the part actually sold for.

GTX750ti should be in your budget, around $100 and will be a nice upgrade and is appropriate for your Q9550.
Do not buy an overclocked version that needs an added 6 pin power lead which your psu probably does not have.

There are low profile versions if needed to fit in your case.

FWIW:

Your Q9550 has a passmark rating of 4021 and a single thread rating of 1201.
A modern $65 intel G4560 has a passmark rating of 5283 and a single thread rating of 1987.
The single thread rating is what is most important for games.

Buying a good graphics card is fine, it can be easily moved to a different build.
Ditto for a ssd.

But... I would otherwise not spend money on such an old gen pc.