5.1 vs 7.1 and onboard audio realtek ALC889

[Archnemesis]

Building a pc soon and i've got a few noob audio questions. I want to use the pc for gaming and as a home theater pc for blue ray and for music.

1) what is the difference between 5.1 and 7.1?

2)is 7.1 supported by games/blueray?

3)if the motherboard has an onboard audio chipset (realtek ALC889) is that good enough or should i get another audio processor? I've been told that the onboard audio is always garbage and that I'll need to upgrade it. I'd like another opinion or
two.

motherboard im considering is MSI 890FXA-GD70 board has optical audio output
newegg link:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130274
realtek link:
http://www.realtek.com/products/productsView.aspx?Langid=1&PFid=28&Level=5&Conn=4&ProdID=173

4) lastly, if i do want to utilize the 7.1 audio, any suggestions on a receiver/speaker package in the $300 range or less?

thanks in advance.

 

[astrallite]

1) 2 more speakers

2) - Blu Rays are mostly in 5.1, although I have seen a 6.1 DTS-Master in my movie collection.
- Games are in 5.1. If you have 7 satellites the surrounds rears will mirror the output from the surrounds.

3) They are about as good as the typical desktop speakers you see people using. I think they are well paired.

4) I would suggest craigslist or ebay. I suppose an Onkyo HT-S3300 could fit your budget. It's not very good, but it's probably the best you can find for $300.