you didn't exactly specify the graphics card. And no GPU goes by that name. HD series is different and older, R7 series is different. The brand ATI hasn't been used since, I don't know, HD 4000? Anyways, please specify which GPU you own, then only I can suggest an upgrade. You can use GPUZ software to get mode details about your current GPU. However, the best AMD R series GPU under £ 150 would be AMD Radeon R9 380. Hope that helps.