GeForce GTX 275 vs Radeon HD 4870 512MB

Intro

Compare those specifications to the Radeon HD 4870 512MB, which comes with core speeds of 750 MHz on the GPU, and 900 MHz on the 512 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 512MB		150 Watts
GeForce GTX 275		219 Watts
	Difference: 69 Watts (46%)

Memory Bandwidth

In theory, the GeForce GTX 275 should be 10% faster than the Radeon HD 4870 512MB in general, due to its higher bandwidth. (explain)

GeForce GTX 275		127008 MB/sec
Radeon HD 4870 512MB		115200 MB/sec
	Difference: 11808 (10%)

Texel Rate

The GeForce GTX 275 will be much (approximately 69%) more effective at anisotropic filtering than the Radeon HD 4870 512MB. (explain)

GeForce GTX 275		50640 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 20640 (69%)

Pixel Rate

If running with high levels of AA is important to you, then the GeForce GTX 275 is superior to the Radeon HD 4870 512MB, and very much so. (explain)

GeForce GTX 275		17724 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 5724 (48%)

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 maximum amount of information (in units of MB per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster 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 number of texture map elements (texels) that are applied per second. This 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 video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the 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 called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant 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 max fill rate.