Can the new iMac's Graphics Cards be Upgraded?

I was thinking about getting a new 20" iMac, but I was wondering their graphics cards can be upgraded, also how good is the ATI Radeon HD 2600 PRO 256mb card that comes with them.

Can the new iMac's Graphics Cards be Upgraded?
No, the 24" iMac appears to be the only iMac that can have its graphics card upgraded.





The ATI Radeon HD 2600 PRO 256mb is pretty good, but nVidia's cards are faster and cheaper. You currently cannot get nVidia cards on iMacs.





Lol, the guy below me posted the article.
Reply:One of the biggest bugbears that power users have had with the iMac range is the fact that the graphics card has always been impossible to upgrade, making each and every iMac tied to the graphics card that it comes with. Yeah, yeah, so what, it's an all-in-one computer for general consumers, right? Maybe so, but until Apple releases a fully upgradable mid-range Mac, there will always be a community of not quite pro, not quite consumer Mac users that dream of buying an affordable and tweakable machine from their computer manufacturer of choice. That's why the news that the 24-inch iMac's graphics card is potentially upgradable is causing such a stir. Apparently Apple decided to opt for a Mobile PCI Express Module (MXM for short) as the connection method for the 24-inch iMac's graphics card. This standard was originally designed by NVIDIA for use in high-end gaming laptops -- indeed, the MXM's official page exclusively mentions "upgradeable notebook graphics". Unfortunately for the aforementioned mid-range Mac dreamers, this is far from a viable upgradeable graphics card solution. For a start, Apple has said that users won't have access to the graphics card and even if hackers succeed in gaining access to the slot, there are currently no stand-alone MXM compatible graphics cards on the market: that makes this the modern day equivalent of the infamous mezzanine slot from the original, supposedly expansion slot-free CRT iMacs. So, if you're a budget-minded Mac user comfortable with tinkering around in your machine, you better get back to praying for that Cube resurrection.