Radeon HD 4870 X2 vs Radeon HD 4890 2GB

Intro

The Radeon HD 4870 X2 features core clock speeds of 750 MHz on the GPU, and 900 MHz on the 1024 MB of GDDR5 memory. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Compare all of that to the Radeon HD 4890 2GB, which uses a 55 nm design. ATi has clocked the core frequency at 1000 MHz. The GDDR5 RAM runs at a frequency of 975 MHz on this specific card. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 ROPs.

Price Comparison

Please note that the price comparisons are based on search keywords, and might not be the exact same card listed on this page. We have no control over the accuracy of their search results.

Radeon HD 4870 X2 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 4890 2GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	Radeon HD 4870 X2	Radeon HD 4890 2GB
Manufacturer	ATi	ATi
Year	Aug 12, 2008	Apr 2, 2009
Code Name	R700	RV790 XT
Fab Process	55 nm	55 nm
Bus	PCIe 2.0 x16 (PCIe bridge)	PCIe 2.0 x16
Memory	1024 MB (x2)	2048 MB
Core Speed	750 MHz (x2)	1000 MHz
Shader Speed	N/A MHz (x2)	(N/A) MHz
Memory Speed	900 MHz (x2)	975 MHz
Unified Shaders	800(160x5) (x2)	800(160x5)
Texture Mapping Units	40 (x2)	40
Render Output Units	16 (x2)	16
Bus Type	GDDR5	GDDR5
Bus Width	256-bit (x2)	256-bit
DirectX Version	DirectX 10.1	DirectX 10.1
OpenGL Version	OpenGL 3.0	OpenGL 3.0
Power (Max TDP)	350 watts	190 watts
Shader Model	4.1	4.1
Bandwidth	230400 MB/sec	124800 MB/sec
Texel Rate	60000 Mtexels/sec	40000 Mtexels/sec
Pixel Rate	24000 Mpixels/sec	16000 Mpixels/sec

Memory Bandwidth: Bandwidth is the maximum amount of data (measured in megabytes per second) that can be transported past the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.