Yes i know its pixmania but this is the cheapest 4870 around.
Here is the spec
Sapphire?s Radeon HD 4870 is designed to meet the needs of the most experienced users. The Radeon HD 4870 is geared towards gamers searching for a maximum number of images per second when they?re playing the latest next-generation video games. Photography fans and those of you with an eye for graphics will be more than pleased with the Radeon HD 4870, because it displays the most striking images in high definition. The clock frequency of the 750 MHz graphics processor highlights subtle tones and finite details in your applications, while its 512 MB DDR5 RAM guarantees the fluidity you need to eliminate image lag. Immerse yourself in a world of 3D graphics with the Radeon HD 4870 from Sapphire!
Technical Specifications Graphics Processor ATI Radeon HD 4850
Processor Frequency 750 MHz
Exchange Interface Memory/Processor 256-bit
Memory 512 MB GDDR5
Bus PCI-E x16, 2.0
Memory Frequency 3600 MHz
DirectX 3D Hardware DirectX 10.1
OpenGL OpenGL 2.0
Outlets Dual DVI-I / TVO / HDTV outputs (via cable)
HDMI (via DVI/HDMI dongle)