The Radeon HD 4855 was a graphics card by ATI, launched on January 3rd, 2010. Built on the 55 nm process, and based on the RV770 graphics processor, in its RV770 PRO variant, the card supports DirectX 10.1. Since Radeon HD 4855 does not support DirectX 11 or DirectX 12, it might not be able to run all the latest games. The RV770 graphics processor is an average sized chip with a die area of 256 mm² and 956 million transistors. Unlike the fully unlocked Radeon HD 4870, which uses the same GPU but has all 800 shaders enabled, ATI has disabled some shading units on the Radeon HD 4855 to reach the product's target shader count. It features 640 shading units, 32 texture mapping units, and 16 ROPs. ATI has paired 512 MB GDDR5 memory with the Radeon HD 4855, which are connected using a 256-bit memory interface. The GPU is operating at a frequency of 575 MHz, memory is running at 900 MHz (3.6 Gbps effective). Being a dual-slot card, the ATI Radeon HD 4855 draws power from 1x 6-pin power connector, with power draw rated at 110 W maximum. Display outputs include: 1x DVI, 1x HDMI 1.3a, 1x VGA. Radeon HD 4855 is connected to the rest of the system using a PCI-Express 2.0 x16 interface. The card measures 220 mm in length, and features a dual-slot cooling solution.