GeForce GTX 650 vs Radeon HD 4870 512MB

Intro

Compare those specs to the Radeon HD 4870 512MB, which features GPU clock speed of 750 MHz, and 512 MB of GDDR5 RAM running at 900 MHz through a 256-bit bus. It also features 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 650		64 Watts
Radeon HD 4870 512MB		150 Watts
	Difference: 86 Watts (134%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 512MB should be quite a bit faster than the GeForce GTX 650 in general. (explain)

Radeon HD 4870 512MB		115200 MB/sec
GeForce GTX 650		80000 MB/sec
	Difference: 35200 (44%)

Texel Rate

The GeForce GTX 650 will be a small bit (more or less 13%) better at texture filtering than the Radeon HD 4870 512MB. (explain)

GeForce GTX 650		33856 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 3856 (13%)

Pixel Rate

The GeForce GTX 650 will be much (more or less 41%) more effective at full screen anti-aliasing than the Radeon HD 4870 512MB, and also will be capable of handling higher screen resolutions without losing too much performance. (explain)

GeForce GTX 650		16928 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 4928 (41%)

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 megabytes per second) that can be moved over the external memory interface within a second. The number is calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video 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 the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.