I am building my first computer with a bugdet of about $900. I am planning on playing Call of Duty Black Opps 2, Portal 2, and Farcry 3 on maxed out settings on a constant 60fps. Would getting the amd radeon 7850 let me do that, or should I ge the 7870?
I am using these parts aswell:
Intel i5 3570k 3.4ghz
Gigabyte ZA-Z77-HD3 LGA 1155 Motherboard
8GB Corsair Vengance 240-pin DDR3
You won't get +60 fps constant maxed out in Far Cry 3 with 7850 (I have that card 2 gb version) but it's still very playable at max settings and you could probably push it up to +60 fps with some overclocking. I haven't overclocked mine yet since I haven't felt the need for it.
I currently have a MSI HD 7850 2GB card.
I have a question as to if I should by a 7870, or get a second 7850 for crossfire, which way would yield better performance?
By using the 7870 you will see an increase of 10 to 20 fps (usually less than 15) in most games...but with a crossfire you will get WAY more performance. In some games ,you can even achieve a 80% fps boost by crossfiring two cards (e.g. Trine 2) ,which would mean almost double fps in theory... so I would definitely recommend crossfiring ,instead of wasting the money on another card ,which will only bring a minor improvement...
Ofc make sure that your PSU can handle that extra card.