My first iMac for Photography, help!

[gabi8]

Hello friends
First of all, Sorry for my english but it's my mother tongue and sure I have some mistakes...
I'm new in the Mac world and I'm looking to buy a new desktop computer. My election is an iMac, but I'm not very sure of which one.
Now I'm working with a windows computer and I use the computer to the normal use (internet, mail, some documents and spreadsheets, watch some movies, etc) and for one of my hobbies, the photography. I have a Reflex Camera and I process my RAW pictures with lightroom and photoshop.
My first election was the basic iMac, the 20 inch with 2GB and I was thinking to expand the memory in the future, but now I have some doubts.
The screen size is not very important for me, indeed I prefer the 20 ones because I have a small flat and the 24 is a bit big to my table... :-( but I have the doubt with the graphic card. I was listening that the 9400M is not a very good card. My first thought was that to my use (photograph edit) the card is not very important (more important is the RAM size) but with the new OS SL which use the GPU to make some mathematical operations the things could be different.
I'm not sure if for my non professional use the big difference of money is justified or not between the 3 iMac (20 with 9400M, 24 with 9400M and 24 with G120).
Can you help me? Someone who uses the iMac to this things could advise me.
Thank you!

 

[Hellhammer]

Photoshopping doesn't need good GPU, it more RAM and CPU related. Just get the base 20" or 24" and add RAM later on

 

[liamwillib]

I agree with the above to the point that the GPU will not make a difference to you at the moment. Although from your post I think you already know that.

I get the idea that what you want to know is will snow leopard give you a performance gain through open cl in the future, and will this gain be bigger if you get a good graphics card now. From the small amount I have read it seems as if your logic is correct, however I would wait until someone with a better understanding shares some knowledge.

I also seem to remember that CS4 on windows can utilise multiple processors OR graphics cards but this was skipped on the mac version this time for some reason. Sorry I can't be more specific as to which one (multicore or GPU), just remember reading somewhere, thought it could be something to read up on.

 

[gabi8]

Thank you very much for your answers.
liamwillib, This is exactly my doubt, I know than the graphic card hasn't a big importance to the photho edit and it's in 3D aplications and games when you have the max performance of it and, as you say, my doubt is if with SL and the open cl this little difference of hardware could be bigger and if I will see some gain.
Thank you one more time and will be very grateful is someone have more ideas.

 

[Hellhammer]

Thank you very much for your answers.
liamwillib, This is exactly my doubt, I know than the graphic card hasn't a big importance to the photho edit and it's in 3D aplications and games when you have the max performance of it and, as you say, my doubt is if with SL and the open cl this little difference of hardware could be bigger and if I will see some gain.
Thank you one more time and will be very grateful is someone have more ideas.

Dedicated GPU is always a big plus for everything. If you're planning to do some gaming or 3D desiging, 9600GT is a must and of course you'll get more advantage of OpenCL when SL comes.

Also, 9600GT machines have higher resale value.

Take a look at refurb store, there you can get prev gen MBP with 9600GT for less than 1400 dollars