Shouldn't the 20 inch 2.4GHz iMac be faster than the 2.4GHz 24 inch iMac?

Not really. The card won't have much of a problem rendering a couple hundred-thousand pixels extra. It is really a non issue. And, since there is more surface area in the iMac it might run better due to better dissipation of heat. A cool CPU is a happy CPU.

IF there was one, it'd be a miniscule one.

It always depends on the benchmark you are comparing.
If you compare a game at their native resolution, then yes the 20" will be faster. But you can run a game perfectly at a lower resolution on the 24". So if both iMacs run the same game on the same resolution, the performance is the same.
Everything else than 3D is not affected by the pixel size. Imho even not video. Because the calculations have to be done for the native video resolution which afterward is transformed to a lower resolution in the video card (which does take a non measurable time).

Yes, it will be faster. Basically you'll run both of them in 1680 x 1050 in games, just the image will be larger on the 24".

TheSelfishGene said:

Yes, it will be faster. Basically you'll run both of them in 1680 x 1050 in games, just the image will be larger on the 24".

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TheSelfishGene said:

Yes, it will be faster. Basically you'll run both of them in 1680 x 1050 in games, just the image will be larger on the 24".

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That doesn't make sense to me? You would want the game in the native resolution of the monitor.

TheSelfishGene said:

Yes, it will be faster. Basically you'll run both of them in 1680 x 1050 in games, just the image will be larger on the 24".

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Umm, nope! The GPU is better on the 24" so it will handle more intensive operations especially screen redraw.

docprego said:

They have the exact same specifications except for screen size. The 20" native resolution is 1680 x 1050 pixels. The 24" native resolution is 1920 x 1200 pixels.

Because everything is equal doesn't the 20" have an easier job to do? It has a lot less pixels to display;1,764,000 for the 20" and 2,304,000 for the 24".

Just a thought...

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HLdan said:

Umm, nope! The GPU is better on the 24" so it will handle more intensive operations especially screen redraw.

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Both have the HD 2600 GPU. Are you thinking of the old iMacs?