GeForce GTX 275 vs Radeon HD 4890 1GB

Intro

The GeForce GTX 275 makes use of a 55 nm design. nVidia has set the core frequency at 633 MHz. The GDDR3 RAM works at a speed of 1134 MHz on this specific card. It features 240 SPUs along with 80 Texture Address Units and 28 Rasterization Operator Units.

Compare that to the Radeon HD 4890 1GB, which makes use of a 55 nm design. ATi has clocked the core speed at 1000 MHz. The GDDR5 memory runs at a speed of 975 MHz on this particular card. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

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 GTX 275 Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Radeon HD 4890 1GB Amazon.com Other US-based stores Amazon.co.uk Amazon.de Amazon.fr

Specifications

Model	GeForce GTX 275	Radeon HD 4890 1GB
Manufacturer	nVidia	ATi
Year	April 9, 2009	Apr 2, 2009
Code Name	G200b	RV790 XT
Fab Process	55 nm	55 nm
Bus	PCIe x16 2.0	PCIe 2.0 x16
Memory	896 MB	1024 MB
Core Speed	633 MHz	1000 MHz
Shader Speed	1404 MHz	(N/A) MHz
Memory Speed	1134 MHz	975 MHz
Unified Shaders	240	800(160x5)
Texture Mapping Units	80	40
Render Output Units	28	16
Bus Type	GDDR3	GDDR5
Bus Width	448-bit	256-bit
DirectX Version	DirectX 10	DirectX 10.1
OpenGL Version	OpenGL 3.1	OpenGL 3.0
Power (Max TDP)	219 watts	190 watts
Shader Model	4.0	4.1
Bandwidth	127008 MB/sec	124800 MB/sec
Texel Rate	50640 Mtexels/sec	40000 Mtexels/sec
Pixel Rate	17724 Mpixels/sec	16000 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.