GeForce GTS 250 1GB vs Radeon HD 4770

Intro

Compare those specifications to the Radeon HD 4770, which comes with core clock speeds of 750 MHz on the GPU, and 800 MHz on the 512 MB of GDDR5 RAM. It features 640(128x5) SPUs as well as 32 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4770		80 Watts
GeForce GTS 250 1GB		145 Watts
	Difference: 65 Watts (81%)

Memory Bandwidth

In theory, the GeForce GTS 250 1GB is 38% faster than the Radeon HD 4770 in general, because of its higher data rate. (explain)

GeForce GTS 250 1GB		70400 MB/sec
Radeon HD 4770		51200 MB/sec
	Difference: 19200 (38%)

Texel Rate

The GeForce GTS 250 1GB is quite a bit (more or less 97%) better at anisotropic filtering than the Radeon HD 4770. (explain)

GeForce GTS 250 1GB		47232 Mtexels/sec
Radeon HD 4770		24000 Mtexels/sec
	Difference: 23232 (97%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 4770 is a better choice, but only just. (explain)

Radeon HD 4770		12000 Mpixels/sec
GeForce GTS 250 1GB		11808 Mpixels/sec
	Difference: 192 (2%)

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: Bandwidth is the largest amount of information (measured in MB per second) that can be moved past the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to 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 reach the max fill rate.