Q4 is the months when a company releases there products. Q stands for Quarter so Q1-January Feburary and March Q2-April May and June Q3- July August September Q4- October November December. I believe NVIDIA i releasing there New 800 series GPU in Q1 or Q2 of 2014 hope that helped
Not sure if it will be available for purchase at that time but they might reveal it but im thinking around Q4 also