Not really. I went from 3GB to 4GB when DDR2 memory was cheaper and the system only recogized 3.2 of the 4 and I really didn't notice any difference. Only a 64-bit system will utilize all 4GB. If you have 3GBs, that means you will most likely have to pull out two 512s and get two 1GB sticks. 2GB is only $30 at Crucial so it's not that bad. I think when I got it, it was $18. It's up to you.
Yes, have 2X1gb + 2X512mb, so would need to remove two 512...I think I'll stick to your words and leave it as it is, quite happy with my pc set up now. Speed is not too bad at all...
Thanks again for your help and time.
In response to freakmarket, I do not believe the graphics chip in the 6670 and 5670 are EXACTLY the same. I'm pretty sure from having extensively researched this in the past week (to buy a video card for my new Inspiron 620) that the 6670 has 480 stream processors vs 400 for the 5670. However, other than that they are pretty much exactly the same. And reading a video card review site, the PassMark rating for the 6670 is just barely higher than the 5670. The difference is so slight that you may not notice any difference in actual use between the two cards. So I opted for the less expensive 5670 and got one with GDDR5 RAM, which should improve throughput over a DDR3 model.
On the subject of power, it's interesting that the 6570 with DDR3 has a rated TDP of only 44 watts.
Even some mini-ITX power supplies should be able to handle that.