GeForce GTX 275 vs Radeon HD 4890 2GB

Intro

Compare those specifications to the Radeon HD 4890 2GB, which features a GPU core clock speed of 1000 MHz, and 2048 MB of GDDR5 RAM set to run at 975 MHz through a 256-bit bus. It also is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 2GB		190 Watts
GeForce GTX 275		219 Watts
	Difference: 29 Watts (15%)

Memory Bandwidth

Performance-wise, the GeForce GTX 275 should in theory be a small bit better than the Radeon HD 4890 2GB overall. (explain)

GeForce GTX 275		127008 MB/sec
Radeon HD 4890 2GB		124800 MB/sec
	Difference: 2208 (2%)

Texel Rate

The GeForce GTX 275 will be a lot (approximately 27%) faster with regards to texture filtering than the Radeon HD 4890 2GB. (explain)

GeForce GTX 275		50640 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 10640 (27%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce GTX 275 is superior to the Radeon HD 4890 2GB, but not by far. (explain)

GeForce GTX 275		17724 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 1724 (11%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of data (counted in megabytes per second) that can be moved past the external memory interface in a second. It is worked out by multiplying the bus width by its memory clock speed. If it uses DDR type memory, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate 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 outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.