GeForce 9800 GX2 vs Radeon HD 4790

Intro

The GeForce 9800 GX2 features a GPU core speed of 600 MHz, and the 512 MB of GDDR3 RAM runs at 1000 MHz through a 256-bit bus. It also is made up of 128 SPUs, 64 TAUs, and 16 Raster Operation Units.

Compare those specifications to the Radeon HD 4790, which features a core clock frequency of 600 MHz and a GDDR5 memory speed of 800 MHz. It also makes use of a 256-bit bus, and uses a 55 nm design. It is made up of 640(128x5) SPUs, 32 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.

GeForce 9800 GX2 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 4790 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	GeForce 9800 GX2	Radeon HD 4790
Manufacturer	nVidia	ATi
Year	Mar 2008	2009
Code Name	G92	RV790
Fab Process	65 nm	55 nm
Bus	PCIe x16 2.0	PCIe 2.0 x16
Memory	512 MB (x2)	512 MB
Core Speed	600 MHz (x2)	600 MHz
Shader Speed	1500 MHz (x2)	(N/A) MHz
Memory Speed	1000 MHz (x2)	800 MHz
Unified Shaders	128 (x2)	640(128x5)
Texture Mapping Units	64 (x2)	32
Render Output Units	16 (x2)	16
Bus Type	GDDR3	GDDR5
Bus Width	256-bit (x2)	256-bit
DirectX Version	DirectX 10	DirectX 10.1
OpenGL Version	OpenGL 3.0	OpenGL 3.0
Power (Max TDP)	197 watts	(N/A) watts
Shader Model	4.0	4.1
Bandwidth	128000 MB/sec	102400 MB/sec
Texel Rate	76800 Mtexels/sec	19200 Mtexels/sec
Pixel Rate	19200 Mpixels/sec	9600 Mpixels/sec

Memory Bandwidth: Bandwidth is the max amount of information (measured in MB per second) that can be transferred past the external memory interface in one second. It is worked out by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.