This might be a really stupid question, but can you use a graphics card with a PCI Express 3.0 x 16 on a motherboard with PCI Express 2.0 x 16 ports?
I've looked online and there are a few people with ridiculously stupid comments like "i may have broken a contact, but i took it back and got a new one since its obviously the port's fault" which is obviously not credible, so since there's a lack of comments saying it doesnt work, im assuming it does?
Here's what I'm looking at:
CPU: AMD FX-8120 (3.1 GHz 8 core with 8MB L2 and L3 cache, probably doesnt matter but including it just to be safe)
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103961&Tpk=AMD%20FX8120
Motherboard: Gigabyte GA990 FXA UD3 with an AM3+ socket, 6GB/s USB3.0 compatible
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128514
GPU: XFX Double D (if you know what I mean ;) haha) FX-787A-CDFC Radeom HD7870 GHz edition, 2GB 256 bit GDDR5 with a PCI Express 3.0x16.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150605
I am not planning to run CrossFire immediately, I would like to complete the build, run some games and see how the graphics performance is, then if necessary go for CrossFireX, so it is an option but based on the reviews I've seen I probably won't end up needing it since I'm fine on medium-high settings or medium on more intensive games.
Again I'm really sorry if this is stupid, I'm a programmer who is somewhat new to building hardware, I've built a couple PC's but it's always been a matter of someone handing me the hardware and the chassis and my job being just to put it all together, not selecting hardware and ensuring compatibility.
Thanks in advance XD