ASUS kicked off its Radeon R9 280 lineup with a pair of DirectCU II series graphics cards, one which sticks to AMD reference clock speeds of 827 MHz core, 933 MHz boost, and 5.00 GHz memory; and a TOP variant, which offers clock speeds of 874 MHz core, 980 MHz boost, and 5.20 GHz memory. Both cards are based on a board design that's not too different from that of the R9 280X DirectCU II series, featuring a custom-design PCB, and the company's new generation DirectCU II cooling solution, which features the CoolTech fan that combines a lateral blower with a conventional fan impeller. Based on the 28 nm "Tahiti" silicon, the Radeon R9 280 features 1,792 stream processors 112 TMUs, 32 ROPs, and a 384-bit wide GDDR5 memory interface, holding 3 GB of memory.