The 4850 is a midrange gaming card from ATI's last generation. From what I understand is Sims3 is not that demanding and my guess is a 4850 will run this with absolutely no issues. However, if you run other games, the 4850 might not fair as well. If you intend to play the Sims and that is it, I wouldn't worry about it and get the 4850 if it is in your budget. However, if you want to make sure this PC can handle future games, I would look at something better. OR you can always just upgrade the 4850 down the road. If the PC handles the 4850 the PSU unit should be able to run further cards. My guess is the PC you are looking at is a good price, this is because the 4850 is selling at a pretty good price right now at least in the US. It's a good card for a limited budget.