Here is the speed difference (GPU wise)

[slayerizer]

I sampled benchmark data from from Windows to give an overview of the power of each cards.

Take note of the notebook resolution, results should be slower with higher res found in iMacs.

Unigine Heaven 2.1 - high, Tesselation (normal), DirectX11 1280x1024

Here are the average score for each card

Cards found in 21"
Model 1 : 640GT : ~23.9 (ddr5)
Model 2 : 650GT : ~28.3


Cards found in 27"
Model 1 : 660m : ~32.6fps
Model 2 : 675mx: ~54.2fps
Model 2 - option 150$ USD : 680mx: no data but 680m did : ~72.9 fps


for reference

i7 HD 4000: ~12.1fps (same resolution)


the CPU comparison is here : http://forums.macrumors.com/showthread.php?t=1499257

I modified the card name with hyperlinks, so anyone could inspect the source reference I used for this compilation.


DISCLAIMER
I have personally no preference and I have no current intention to buy the current gen.

[kaellar]

are you sure 640m from your scores uses GDDR5 like iMac's one and not DDR3 like most of other manufacturers put into their products?

[slayerizer]

Originally Posted by kaellar

are you sure 640m from your scores uses GDDR5 like iMac's one and not DDR3 like most of other manufacturers put into their products?

4096 MB 645 - 709 / 1000MHz 1024MB GDDR5 ForceWare 23.2 fps

[Scott6666]

What's the benchmark on the HD4000?

[slayerizer]

Originally Posted by Scott6666

What's the benchmark on the HD4000?

i7 HD 4000: ~12.1fps (same resolution)

----------

I modified the card name with hyperlinks, so anyone could inspect the source reference I used for this compilation.


DISCLAIMER
I have personally no preference and I have no current intention to buy the current gen.

[Siderz]

Why did you/someone lower the resolution?

Nobodies going to be using the iMac lower than 1920x1080...

[slayerizer]

Originally Posted by Siderz

Why did you/someone lower the resolution?

Nobodies going to be using the iMac lower than 1920x1080...

I think you didn't read the text in the top message. There are no current imac 2012 gpu benchmark results as we speak.

For reference, I took results from Windows computers running a popular benchmark tool. The most common resolution for the cards listed here was the resolution you saw listed in the first post.

This is suppose to give hints about the performance relation between each models.

[Siderz]

Originally Posted by slayerizer

I think you didn't read the text in the top message. There are no current imac 2012 gpu benchmark results as we speak.

For reference, I took results from Windows computers running a popular benchmark tool. The most common resolution for the cards listed here was the resolution you saw listed in the first post.

This is suppose to give hints about the performance relation between each models.

Sorry, I thought you meant Windows on Boot Camp.

I guess I'll just wait for a proper benchmark test then.

[Galatian]

Originally Posted by Siderz

Sorry, I thought you meant Windows on Boot Camp.

I guess I'll just wait for a proper benchmark test then.

Why? This still gives an overview on how well the certain models are going to perform. When choosing the same resolution you actually have a good point of comparison. Besides it show that games using the newest Unreal Engine cannot be run on the 21.5" iMac with native resolution. You will most certainly have to scale down.

Thanks for the comparison charts!

[Siderz]

Originally Posted by Galatian

Why?

Because I want to.

[Galatian]

Originally Posted by Siderz

Because I want to.

Granted, but then don't say "proper" benchmark, because these are proper benchmarks

[Siderz]

Originally Posted by Galatian

Granted, but then don't say "proper" benchmark, because these are proper benchmarks

These aren't 'proper' benchmarks of the iMac.

The only similarity between the notebook he used and the iMac is that they have the same GPU.

They're not even running the same OS, which could account for a lot.

[slayerizer]

Originally Posted by Galatian

Besides it show that games using the newest Unreal Engine cannot be run on the 21.5" iMac with native resolution. You will most certainly have to scale down.

just note that Unigine Heaven is NOT Unreal Engine (from Epic). You can license it but they did a tech demo often used to bench video cards. Unreal engine can scale up or down depending of the configuration.

but I'm still convince it gives a good overview of the different models. I think if you buy 27", the 680mx is one of the cheapest option.

[Scrapula]

Thanks! You can see just how much the 675 blows away everything else. The 680mx will really rock.

[Galatian]

Originally Posted by Siderz

These aren't 'proper' benchmarks of the iMac.

The only similarity between the notebook he used and the iMac is that they have the same GPU.

They're not even running the same OS, which could account for a lot.

True but it show how well they scale. A 650M is not going to be faster then the 680MX on OSX, otherwise there would be huge software issue. The hardware is comparable and I believe the Unigine is pretty stressing on the GPU and not so much on the other hardware this just be pretty representative of what you can expect on the new iMacs.