Comparing my own computer to 21.5" iMac

I recommend using search and research.

This question has been asked time and time again except all you've done is rephrase it to match your situation. Of course the iMac can Photoshop, Movies (even FCS), Internet, Word/Pages etc. and it can even do some 3D games. If you can afford it and wish to buy it... do! If not... don't!

To personally answer your question:-
The 9400m is a mobile GPU so not as good but most would recommend ATi over nVidia in a Mac due to better driver support. Processor is quad versus duo, kinda depends on day-to-day application. The higher clock speed would certainly benefit a lot of applications.

Probably not a downgrade but more of a direct swap. If you can afford it go i5 on a 27" if not go ATi on the 21.5"

 

I have the 21.5" base iMac with the Core2Duo and 9400M, and it is very fast and handles graphics well. That said, if I were a gamer (which I'm not), you probably do want a dedicated graphics card. It just makes sense if most of what you do is graphics-intensive.

 

Your current 9500GT is about twice as fast, maybe more, than the 9400M.
The Radeon 4670 is about twice as fast as your 9500GT.

The Phenom is quad core running at 2.2ghz vs a dual core processor running at 3ghz. Overall its about even, with the higher clock speed helping apps that aren't multithreaded, and the quad core helping apps that are better multithreaded.

As someone else said, its not much of an upgrade over what you have now, its more of a "sidegrade".

 

Hardware wise it's not much of an upgrade. Software wise it's a huge upgrade. THat's the thing that counts.

 

-NVidia GeForce 9500 GT (256MB) vs NVidia GeForce 9400m vs ATI Radeon HD 4670 (256MB)
-The 4670 is the best of the three cards.

-AMD Phenom 9500 Quad Core (2.20GHz) vs Intel Core 2 Duo (3.06GHz)
-The AMD has more cores, but the Intel is clocked at a higher speed. For the tasks you've listed, the C2D is more than enough.

-3GB RAM vs 4GB RAM (logically, the 4GB)
-Obviously the 4GB, especially since it's DDR3, and yours is most likely DDR2.

-Playing 3D games, Photoshop, movies, internet, music, etc.
-The iMac does a spectacular job at all of those.

Overall, I think you should go for the higher end 21.5" model. However, if you don't have the money, the base model will do just fine.

 

I don't want to hijack this thread but I just wanna ask one question. I am currently using a 250GB HDD and have 125GB free. I do light work with photoshop, watch HD videos, surf net and listen to music. Will the base model do? I'd probably play Football Manager 2010 and MAYBE MW2.

I have a feeling the base will be enough but just wanna hear what someone thinks.