Which one should I choose?
R7 250
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202052
HD 7770
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202011
Which one should I choose?
R7 250
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202052
HD 7770
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202011
IMO: 7770 - only 1GB but more stream processors and much faster memory (GDDR5 not 3).
Save up for a 7850, that is what I would do if it was my money. Prices will probably drop soon on those too.