GeForce GTX 275 vs Radeon HD 7770

Intro

Compare all that to the Radeon HD 7770, which comes with a clock frequency of 1000 MHz and a GDDR5 memory frequency of 1125 MHz. It also features a 128-bit bus, and makes use of a 28 nm design. It is comprised of 640 SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7770		80 Watts
GeForce GTX 275		219 Watts
	Difference: 139 Watts (174%)

Memory Bandwidth

As far as performance goes, the GeForce GTX 275 should in theory be a lot better than the Radeon HD 7770 overall. (explain)

GeForce GTX 275		127008 MB/sec
Radeon HD 7770		72000 MB/sec
	Difference: 55008 (76%)

Texel Rate

The GeForce GTX 275 should be quite a bit (more or less 27%) better at AF than the Radeon HD 7770. (explain)

GeForce GTX 275		50640 Mtexels/sec
Radeon HD 7770		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 the winner, but only just. (explain)

GeForce GTX 275		17724 Mpixels/sec
Radeon HD 7770		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 information (in units of megabytes per second) that can be moved past the external memory interface within a second. The number is calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is worked out by multiplying the total amount of texture units by the core 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 applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.