First of all, Linux is not made to be a gaming platform, don't be surprised if you have lags. maybe they will work perfectly, maybe not.
I have an hp myself, very similar to you, more powerful 8gb ddr3. I hope Linux works on your machine, I'll talk about what I know. On my PC:
- I had problems with Wifi drivers.
- On ubuntu 12.04 LTS, I had to set nomodeset to make unity work. Newer versions never worked no matter what I do.
- Suspend and Log out mode did not work because of a graphic card issue,
the screen goes black forever, I had to force shut down using the
power button.
I had these problems, or at least one of them with every Linux distro I used: Archbang, Manjaro, Crunchbang, Linux Mint (Mate and Cinnamon), Linux Mint debian, Fuduntu, Ubuntu. I hope I didn't forget a distro :)
However, now I'm on Xubuntu 13.10 (The latest version) and it works like a charm out of the box on my PC. Xfce is working perfectly, and for some reason I am not experiencing any errors whatsoever. Besides Xfce is lighter than unity, giving you more recourses to play. And in my personal opinion Xfce is much more beautiful that unity.
SuperMulti DVD Burner
.