Play Crysis 2 on a iMac via External Graphic Card

[BumbleBiee]

So I'm new to Mac and I got an iMac 21,
I'm running Win 7 and uses it mostly to play games..
I'm currently playing Crysis without any big problems however Crysis 2 is due to be dropped soon and I dont think it will run on my iMac Mid 2010 21.5´

I checked if it's possible to run Crysis 2 on "Can You Run It?" and it says I cant due to my Graphic Card

Minimum: NVIDIA GeForce 8800 GT 512 MB of memory or higher; ATI/AMD Radeon HD 3850 512Mb RAM or higher
You Have: ATI Radeon HD 4670

Is it possible to upgrade my graphic card, preferably to Nvidia if not Nvidia to ATI Radeon (higher than ATI R 4670)
And if it's not possible to upgrade my Graphic card can I use an External Graphic Card?

[chscag]

You can't upgrade the graphics card in your iMac as it's integrated (soldered) on the logic board. Actually, surface mounted.

I can't answer your question about an external graphics card though, perhaps someone here who has used one can answer.

[CrimsonRequiem]

Seems like this question as been asked before on Apples discussion page.

Doesn't seem very promising. >_<"

[cwa107]

External video cards are severely inhibited by the bandwidth of the external bus. An internal, PCI-e card is going to be an order of magnitude faster than something attached via the comparatively feeble USB bus.

What external cards are useful for is massive multi-monitor setups, but that's about it.