@_Neptunno_:
Well, the truth is that the other day I was using, at work, Photoshop CS to resize several images (a few hundred xD) through a batch process, and wow, there was a moment when it ate 6GB of the 8Gb I have (an i5 I have at work), luckily this didn't happen to me with the Core Duo I had before with 3GB of memory, haha... otherwise I would have died!!
The truth is that with 4GB it runs well today, but at certain times, or depending on what you do, you can regret not having more leeway. Considering the price of memory today, 8GB is very cheap and accessible.
Another thing is that one is broke... so you can hold on with 4GB for a while.
Regards!!
as I say, for gaming and running AutoCAD with 4GB is enough, for certain applications NO and for professional use of AutoCAD not either, just as my micro and my GTX280 graphics card are not suitable, but for sporadic use yes. If the PC is for gaming, I would save the memory money to get an SSD. But remember, this is a personal opinion
regards